1．設(shè)，已知命題；命題，則是成立的

A．必要不充分條件　 B．充分不必要條件C．充分必要條件　 D．既不充分也不必要條件

3．指數(shù)函數(shù)在底數(shù)及這兩種情況下的圖象和性質(zhì)：

圖象
性質(zhì)	(1)定義域：
(2)值域：
(3)過(guò)點(diǎn)，即時(shí)
(4)在上是增函數(shù)	(4)在上是減函數(shù)

　 例3．已知指數(shù)函數(shù)的圖象經(jīng)過(guò)點(diǎn)，求的值(教材第66頁(yè)例6)。

　 例4．比較下列各題中兩個(gè)值的大�。�

　 ；　　　　　 　　　　　　

(教材第66頁(yè)例7)

小結(jié)：學(xué)習(xí)了指數(shù)函數(shù)的概念及圖象和性質(zhì)；

練習(xí)：教材第68頁(yè)練習(xí)1、3題。

作業(yè)：教材第69頁(yè)習(xí)題2。1A組題　 第6、7、8題　

2.指數(shù)函數(shù)(且)的圖象：

例1．畫的圖象(圖(1))．

解：列出的對(duì)應(yīng)表，用描點(diǎn)法畫出圖象

	…	-3	-2	-1.5	-1	-0.5	0	0.5	1	1.5	2	3	…
	…	0.13	0.25	0.35	0.5	0.71	1	1.4	2	2.8	4	8	…

例2．畫的圖象(圖(1))．

	…	-3	-2	-1.5	-1	-0.5	0	0.5	1	1.5	2	3	…
	…	8	4	2.8	2	1.4	1	0.71	0.5	0.35	0.25	0.13	…

指出函數(shù)與圖象間的關(guān)系？

說(shuō)明：一般地， 函數(shù)與的圖象關(guān)于軸對(duì)稱。

1．指數(shù)函數(shù)定義：

一般地，函數(shù)(且)叫做指數(shù)函數(shù)，其中是自變量，函數(shù)定義域是．

練習(xí)：判斷下列函數(shù)是否為指數(shù)函數(shù)。

①　 ②　　　 ③(且)④

⑤　 ⑥　　 ⑦ ⑧．

引例1：某種細(xì)胞分裂時(shí)，由1個(gè)分裂成2個(gè)，2個(gè)分裂成4個(gè)……1個(gè)這樣的細(xì)胞分裂次后，得到的細(xì)胞個(gè)數(shù)與的函數(shù)關(guān)系式是：．

這個(gè)函數(shù)便是我們將要研究的指數(shù)函數(shù)，其中自變量作為指數(shù)，而底數(shù)2是一個(gè)大于0且不等于1的常量。

201. It's a great pleasure to...……(感到)非常愉快. It's a great pleasure to do business with you. 跟你做生意我感到非常愉快. 202. It's customary to...…是習(xí)慣. It's customary to give people gifts on their birthday. 過(guò)生日送禮物是一種習(xí)俗. 203. It's delightful to...……令人很高興. lt's delightful to play by the seashore. 在海濱玩令人很高興. 204.lt's my great honor to...……是我莫大的榮幸. It's my great honor to introduce the governor. 我很榮幸向大家介紹我們的州長(zhǎng). 205. It's (not) good to...……(不)好. It's not good to get into the habit of telling lies. 養(yǎng)成說(shuō)謊的習(xí)慣不好. 206. It's our duty to... ……是我們的責(zé)任. It's our duty to protect the forests from destruction. 保護(hù)森林免遭破壞是我們的責(zé)任. 207. It's wrong to...……是不對(duì)的. It's wrong to read people's private letters without permission.未經(jīng)允許看別人的私人信件是不對(duì)的. 208. It's a shame / pity that... 可惜/遺憾……. It's a shame that you cannot make it to the party tonight. 今晚你不能來(lái)參加聚會(huì),真可惜. 209. It is (really) unbelievable that...……(真)讓人難以置信. It's really unbelievable that such an honest fellow should have betrayed his friends! 這樣一個(gè)老實(shí)人竟會(huì)出賣朋友,真讓人難以置信1 210. It is /will be difficult to...……(會(huì))很難. I think it will be difficult to tell her the truth. 我認(rèn)為告訴她真相會(huì)很難. 211. It'll do you good to...……對(duì)你有好處. I think it'll do you good to drink eight glasses of water every day. 我認(rèn)為每天喝八杯水對(duì)你有好處. 212. Last but not least, ...…最后但同樣重要的是……. Last but not least, I'd love to thank all my teachers and friends. 最后但同樣重要的是,我要感謝我所有的老師和朋友. [經(jīng)典演講句型] 213. Let me explain why...…讓我解釋為什么……. Let me explain why I didn't do my homework. 讓我解釋為什么我沒(méi)做家庭作業(yè). 214. Let me fill you in on... 讓我來(lái)告訴你……. [六星級(jí)句型] Let me fill you in on the company's new policies. 讓我來(lái)告訴你公司的新政策. [ fill sb. in on: 對(duì)某人提供有關(guān)……的情況] 215. (Just) let me know if... 如果……,請(qǐng)告訴我. 1) Let me know if you change your mind. 如果你改變了主意,請(qǐng)告訴我. 2) Just let me know if you don't know how to get to that shop. I will be glad to take you there. 如果你不知道怎么去那家店,請(qǐng)告訴我.我很樂(lè)意帶你去那的. 216. Let me see if... 讓我看看是否……. Let me see if I can be of any help. 讓我看看能否幫上什么忙. 217. Make sure to do sth.-定要做某事. Make sure to leave a note if you go out. 你出去的話一定要留個(gè)條. 218. Maybe it's better to... 可能……會(huì)更好一些. Maybe it's better to stay at the hospital for another few days.你在醫(yī)院再住幾天可能會(huì)更好一些. 219. ... means a great deal to me.……對(duì)我意義重大. Your encouragement means a great deal to me. 你的鼓勵(lì)對(duì)我來(lái)說(shuō)意義重大. 220. My dream / goal / hope / plan is... 我的夢(mèng)想/目標(biāo)/希望所劃是……. My dream is to speak English in three months. 我的夢(mèng)想是三個(gè)月內(nèi)會(huì)說(shuō)英語(yǔ). 221. My point of view is that... 我的觀點(diǎn)是……. My point of view is that everybody should have the right to get an education. 我的觀點(diǎn)是每個(gè)人都應(yīng)該有權(quán)利接受教育. 222. no matter what... …無(wú)論什么……. No matter what happens, I'll always stand by you. 不論發(fā)生什么事,我都永遠(yuǎn)支持你. 223. no one can deny that... 沒(méi)有人能夠否認(rèn)……. No one can deny that the accident was caused by carelessness. 沒(méi)有人能夠否認(rèn)這起事故是由粗心造成的. 224. no sooner...than... 一……就……. [倒裝句型] No sooner had he closed his eyes than he fell asleep. 他一合眼就睡著了. 225. no words can express... 語(yǔ)言難以表達(dá)……./……難以言表. No words can express how surprised and happy I was when I saw the gift. 語(yǔ)言難以表達(dá)當(dāng)我看到那份禮物時(shí)有多么的驚喜. 226. Not until...did... 直到……才……. [倒裝句型] Not until I began to work did I realize how much time I had wasted. 直到我開(kāi)始工作,我才意識(shí)到我已蹉跎了很多歲月. 227. Now that...,…既然/由于……,……. Now that we are alone, we can talk freely. 既然我們單獨(dú)在一起,就無(wú)拘束地聊聊吧. 228. On the condition that... …條件是……. You can leave school early, on the condition that you finish your assignment first. 你可以早點(diǎn)離校,條件是你得先做完作業(yè). 229. On the contrary, ... 正好相反,……. Their criticism did not discourage me. On the contrary, I worked even harder. 他們的批評(píng)并沒(méi)有使我感到氣餒,相反,我比以前更加努力了. 230. On (the) one hand..., on the other (hand), ... 一方面……,另一方面……. On (the) one hand I admire your ability, but on the other (hand) I distrust your judgment. 一方面我欽佩你的才能,但另一方面我不相信你的判斷力. 231. One of the +形容詞最高級(jí)+名詞+is… 最……之一的就是…… One of the most impressive pieces of writing is Hamlet. 給人印象最深的著作之一就是《哈姆雷特》. 232. Personally, I think / believe / feel... 我個(gè)人認(rèn)為/相信/感覺(jué)……. Personally, I think that women play an increasingly important role in society now. 我個(gè)人認(rèn)為女性在社會(huì)中發(fā)揮著越來(lái)越重要的作用. ; 233. Please don't hesitate to... 請(qǐng)隨時(shí)……. Please don't hesitate to contact us if you are in need of assistance. 如果你需要協(xié)助,請(qǐng)隨時(shí)聯(lián)系我們. 234. Please feel free to... …請(qǐng)隨時(shí)……. Please feel free to visit me when you are in Guangzhou. 在廣州的時(shí)候,請(qǐng)隨時(shí)來(lái)找我. 235. Please forgive me for... …請(qǐng)?jiān)�諒我…�? Please forgive me for being late. 請(qǐng)?jiān)�諒我�?lái)晚了. 236. Please give my best wishes to...…請(qǐng)代我問(wèn)候……. Please give my best wishes to your parents. 請(qǐng)代我問(wèn)候你的父母. 237. Recent studies show that... 最近研究表明……. Recent studies show that an increasing number of students go abroad at an early age. 最近調(diào)查表明,越來(lái)越多的學(xué)生在年紀(jì)尚小的時(shí)候就出國(guó)留學(xué)了. 238. Sb. can do nothing but do... 除了做……,某人什么也做不了. Their neighbors tan do nothing but envy their new pool. 他們的鄰居只能羨慕他們的新泳池. 239. Sb. have / has / had no choice but to do... 某人除了做……別無(wú)選擇. We had no choice but to take a taxi for we'd missed the last bus. 由于錯(cuò)過(guò)了最后一班公共汽車,除了乘坐的士,我們別無(wú)選擇. 240. Sb. look(s) as if... 某人看上去好像……. She looks as if she is unfriendly at first. 她起初看上去好像一點(diǎn)都不友好. 241. Something must be done to...…必須采取措施……. Something must be done to change our current examination system. 必須采取措施來(lái)改革我們現(xiàn)行的考試制度. 242. Sorry to bother you, but... …很抱歉打擾你,可是……. Sorry to bother you, but I have a question to ask you. 很抱歉打擾你,可是我有個(gè)問(wèn)題要問(wèn)你. 243. Thanks to... 由于…/多虧…. Thanks to his parents' encouragement and support, he finally realized his dream. 多虧了他父母的鼓勵(lì)與支持,他終于實(shí)現(xiàn)了他的夢(mèng)想. 244. The point is... 重點(diǎn)/關(guān)鍵是……. The point is that you have to keep your promise to help her with her English. 關(guān)鍵是你得遵守諾言,幫她學(xué)習(xí)英語(yǔ). 245. The problem / question is that / whether... 問(wèn)題是……. 1) The problem now is that we're locked out of the house. 現(xiàn)在的問(wèn)題是我們被鎖在門外了. 2) The question is whether they will be able to help us. 問(wèn)題是他們能否幫助我們. 246. The reason why... is...…的原因就是……. The reason why he made such a great achievement is his perseverance. 他之所以取得如此偉大的成就,原因是他堅(jiān)持不懈. [ perseverance n.堅(jiān)持;堅(jiān)定不移] [堅(jiān)持創(chuàng)造輝煌!] 247. The secret of...is to... ...的秘訣是....... The secret of success is to do the common things uncommonly well. 成功的秘訣是將平凡的事做得不平凡. [五星級(jí)名言!李陽(yáng)老師熱烈推薦!] 248. The way I see it, ..…我的看法是……. The way I see it, you should avoid making the same mistake again. 我的看法是你應(yīng)該避免再犯同樣的錯(cuò)誤. 249. This was the moment when...…就是那個(gè)時(shí)候……. This was the moment when I realized that I wanted to be a professional singer. 就是那時(shí)我意識(shí)到自己想成為一名專業(yè)歌手. 250. That reminds me, ... 那提醒了我……./那讓我想起了……. That reminds me, I must get some cash. 這倒提醒了我,我得取一些現(xiàn)金

101. I won't...unless... 除非……否則我不會(huì)……. I won't write to him unless he writes to me first. 我不會(huì)寫信給他的,除非他先寫給我. 102. I used to... 我過(guò)去常�！�…. I used to go play basketball with some of my friends every Saturday afternoon. 以前我和一些朋友每星期六下午都去打籃球. 103. I would advise you to... 我會(huì)建議你……. I would advise you to get up earlier on Mondays, because there's always a traffic jam. 我會(huì)建議你星期一早上早點(diǎn)起床,因?yàn)榭偸菚?huì)塞車. 104. I would appreciate it if... 如果……,我會(huì)非常感激. I would appreciate it if you call me back this evening. 如果你晚上給我回電話,我會(huì)非常感激. 105. I would like to recommend... 我想推薦……. I would like to recommend the Vietnamese cuisine in that restaurant. 我想推薦一下那家餐廳的越南菜. [cuisine n. 烹飪;烹調(diào)風(fēng)格] 106. I would like to... rather than... 我寧愿……也不……. I would like to take a walk rather than watch TV this weekend. 這周末我寧愿散步也不想看電視. 107. I would rather...than... 我寧愿……,而不愿……. I would rather stay at home than go shopping on such humid day. 在這樣潮濕的天氣里,我寧愿呆在家里,也不愿去購(gòu)物. 108. I wouldn't feel happy if... 如果……我會(huì)不高興的. I wouldn't feel happy if you didn't come to my birthday party. 如果你不來(lái)我的生日聚合的話,我會(huì)不高興的. 109. I'd be happy to..., if you'd like. 如果你愿意,我很高興……. I'd be happy to show you around, if you'd like. 如果你愿意,我很高興帶你四處看看. 110. I'd like to know more about... 我想了解更多關(guān)于……. I'd like to know more about the project you are carrying out. 我想更多地了解你們正在進(jìn)行的項(xiàng)目. 111. I'd like to suggest you do... 我想建議你……. I'd like to suggest you take the test when you are still in school. 我想建議你在上學(xué)的時(shí)候就參加這個(gè)考試. 112. I'd like /love to, but... 我很想,但……. I'd love to, but I'm afraid I'm otherwise engaged. 我很想,但恐怕我已經(jīng)另有安排了. [ 拒絕別人邀請(qǐng)的經(jīng)典句型.] 113. I'm (not) certain... 我(不)確定……. I'm certain that you will get over your laziness. 我確信你會(huì)克服你的惰性的. [沒(méi)有什么是不能克服的,只要有決心] 114. I'm afraid I won't be able to... 恐怕我不能……. I'm afraid I won't be able to finish the task before Friday. 恐怕我無(wú)法在星期五之前完成這項(xiàng)任務(wù). 115. I'm busy with (doing)... 我正忙于……. Don't bother me - I'm busy with (doing) my project right now. 別打擾我,我現(xiàn)在正忙于作計(jì)劃呢. 116. I'm considering (doing)... 我正考慮……. I'm considering buying a second-hand computer for I'm short of money now. 因?yàn)楝F(xiàn)在錢不夠,我正考慮買臺(tái)二手電腦. 117. I'm convinced that... 我確信……. I'm convinced that what you said is quite right. 我相信你所說(shuō)的相當(dāng)正確. 118. I'm curious to (do)/about... 我對(duì)(做)……很好奇. I'm curious to know what was happening outside. 我很好奇,想知道外面發(fā)生了什么事. 119. I'm determined to...我決定……. I'm determined to read 10 books this month. 這個(gè)月我決定讀十本書. 120. I'm getting a little concerned about... 我對(duì)……有點(diǎn)擔(dān)憂. I'm getting a little concerned about the results of my TOEFL test. 我對(duì)我的托�？荚嚦煽�(jī)有點(diǎn)擔(dān)憂. [TOEFL = Test of English as a Foreign Language英語(yǔ)作為外國(guó)語(yǔ)的考試(也稱托�？荚�)(美國(guó)大學(xué)對(duì)外國(guó)學(xué)生入學(xué)前的英語(yǔ)測(cè)試)] 121. I'm interested in...我對(duì)……感興趣. I'm interested in joining the English corner. 我有興趣參加英語(yǔ)角. 122. I'm (just) calling to... 我打電話來(lái)是要……. I am (just) calling to confirm my flight number. 我打電話來(lái)是要確認(rèn)我的航班號(hào). 123. I'm (not) sure... 我(不是)很確定……. I'm not sure if I should accept that job offer in Hong Kong. 我不確定我是否應(yīng)該接受香港的那份工作. 124. I'm not very interested in... 我對(duì)……不是很感興趣. I'm not very interested in listening to classical music. 我對(duì)聽(tīng)古典音樂(lè)不是很感興趣. 125. I'm occupied (with)... 我忙于……. I'm occupied with preparing for the final exams; don't bother me! 我正忙著準(zhǔn)備期末考試,別來(lái)打擾我1 126. I'm really fond of... 我的確喜歡……. I'm really fond of surfing the Internet; it is pretty convenient. 我的確喜歡上網(wǎng),上網(wǎng)真的很方便. 127. I'm really / terribly / extremely sorry for... 我對(duì)……感到非常抱歉. I'm really sorry for the delay of the report. 報(bào)告延誤上交,我對(duì)此感到非常抱歉. I28. I've been thinking about... 我一直想……. I've been thinking about going to France to study art. 我一直想去法國(guó)學(xué)藝術(shù). 129. I have a desire to... 我非�？释�……. I have a strong desire to speak good English. 我非常渴望說(shuō)一口流利的英語(yǔ). 130. I've decided to... 我已經(jīng)決定……. I've decided to run for the monitor of our class. 我已經(jīng)決定競(jìng)選班長(zhǎng)了. [run for:競(jìng)選] [瘋狂提醒] 接下來(lái)的四個(gè)句型都是虛擬語(yǔ)氣句型,請(qǐng)瘋狂操練,堅(jiān)決攻克這一難點(diǎn). 131. If I did..., I would... 如果我……,我會(huì)……. If I knew his number, I would phone him. 如果我知道他的電話號(hào)碼,我會(huì)打電話給他的. 132. If I had done..., I would have done... 如果我……,我就會(huì)……. If I had known that you were coming, I would have met you at the airport. 如果我知道你要來(lái),我就會(huì)去機(jī)場(chǎng)接你了. 133. If I were you... I would... 如果我是你……,我就會(huì)……. If I were you, I would get rid of this bad habit. 如果我是你,我就會(huì)改掉這個(gè)壞習(xí)慣. 134. If only...! 真希望……!若是……那該多好啊! If only she would accept my invitation! 要是她接受我的邀請(qǐng)?jiān)摱嗪冒? 135. If it is possible, ... 可能的話……. 1) If it is possible, I'd like to see you tomorrow. 若可能,我想明天見(jiàn)你. 2) If it is possible, lend me your car tonight. 若可能,今晚把你的車借給我. 136. If you ask me, I think... 如果你問(wèn)我,我認(rèn)為……. If you ask me, I think you should practice more. 如果你問(wèn)我,我認(rèn)為你應(yīng)該多加練習(xí). 137. If you want to..., you'll have to... 如果你想……,你將不得不……. If you want to remember more words, you'll have to read a lot in English. 你要是想記住更多的單詞,你就得大量地讀英語(yǔ). 138. In a word... 總之,… In a word, money is something but not everything. 總之,金錢很重要,但它不是萬(wàn)能的. 139. In brief/short, ...,簡(jiǎn)言之,……. 1) In brief, we cannot please everyone all the time. 簡(jiǎn)而言之,我們無(wú)法總是讓每個(gè)人都滿意. 2) In short, science frees us from the bondage of nature. It has made our lives easier and more comfortable.總之,科學(xué)把我們從自然的束縛中解脫出來(lái),使我們生活得更加輕松舒適. [bondage n.束縛;奴役] 140. In conclusion, ...最后,…….聰之,……. In conclusion, I find mutual understanding plays a key role in building a friendly relationship. 總之,我發(fā)現(xiàn)相互理解對(duì)建立友好關(guān)系至關(guān)重要. 141. In general, ... --般而言,……. In general, graduates who speak good English will have more chances than those who don't. 一般而言,會(huì)講流利英語(yǔ)的畢業(yè)生比英語(yǔ)不好的畢業(yè)生機(jī)會(huì)更多. 142. In my opinion /view, ... 我認(rèn)為……. In my opinion, we should never abandon hope for success. 我認(rèn)為我們永遠(yuǎn)都不應(yīng)該放棄對(duì)成功的希望. [abandon..放棄;遺棄] 143. In order to..., you should... 為了..…•,你應(yīng)該..…. In order to understand this essay fully, you should read more about its author. 為了更充分地理解這篇文章,你應(yīng)該多看一些關(guān)于作者的介紹. 144. In other words, ... 換句話說(shuō),……. In other words, you should read and speak English crazily every day. 換句話說(shuō),你應(yīng)該每天瘋狂讀英語(yǔ),說(shuō)英語(yǔ). 145. In that case,… 既然那樣,……. │ In that case, I have no more to say.既然那樣,我沒(méi)什么好說(shuō)的了. 146. ...is of great importance. ......很重要. │ If you want to succeed in life, I think to set a goal for yourself is of great importance. 如果你想在生活中成功,我覺(jué)得為自己確立一個(gè)目標(biāo)是非常重要的. 147. Is it convenient for you to... 你是否方便…… Is it convenient for you to post this letter for me when you go out 你出去的時(shí)候是否方便幫我寄這封信 148. Is it OK if… 如果……可以嗎 Is it OK if I borrow your notebook tonight 我今晚借你的筆記本可以嗎 149. Is it possible to... …有可能嗎 Is it possible to exchange the milk shake for the ice cream 可以把奶昔換成雪糕嗎 [milkshake:奶昔] 150. Is there a better way to... ……有沒(méi)有更好的方法 Is there a better way to search for images on the Internet 在網(wǎng)上搜索圖片有沒(méi)有更好的辦法 151. Is there any chance you could possibly... 你有沒(méi)有可能…… Is there any chance you could possibly come to China 你有沒(méi)有可能來(lái)中國(guó) 152. Is there anything else that... 還有別的……嗎 Is there anything else that you don't understand 你還有什么不懂的地方嗎 153. It appears that... 看來(lái)…,/ 似乎… It appears that great progress has been made in the IT industry. 看來(lái)信息產(chǎn)業(yè)取得了巨大的進(jìn)步. 154. It depends on whether... 這取決于……是否……. It depends on whether you are determined to do it or not. 這取決于你是否決心要做這件事情. 155. It doesn't make sense to...…沒(méi)有任何意義. It doesn't make sense to argue with him. 和他爭(zhēng)論沒(méi)有任何意義. 156. It doesn't matter whether /if... 如果……也沒(méi)關(guān)系. It doesn't matter if you have made mistakes. Learn from your mistakes and you'll make progress. 如果犯錯(cuò)誤了也沒(méi)關(guān)系.從錯(cuò)誤中學(xué)習(xí),你就會(huì)進(jìn)步. 157. It goes without saying that... 理應(yīng)如此/不言而喻. It goes without saying that women should have equal rights and opportunities with men. 女性理應(yīng)擁有和男性平等的權(quán)利和機(jī)會(huì). 158. It makes a / no difference (to sb.) ... (對(duì)某人來(lái)說(shuō))……很重要/無(wú)所謂. It makes no difference to me whether you go or not. 你去不去對(duì)我來(lái)說(shuō)都無(wú)所謂. 159. It occurred to me that... ……浮現(xiàn)于我的腦中.俄想起……. It suddenly occurred to me that ' knew how to solve that problem. 我突然想起我知道怎樣解決那個(gè)問(wèn)題. 160. It won't do any harm to... 沒(méi)有壞處. It won't do any harm to try it. 試試又不會(huì)有什么壞處. 161. It would be wonderful if... 要是……那就太好了. It would be wonderful if we can go visit Mount Emei this summer! 要是今年夏天我們能去峨眉山旅游就好了1 162. It happened that...……很偶然. It happened that I won the football lottery last week. 我上星期偶然中了足彩. [ lottery n. 彩票;獎(jiǎng)券] 163. It helps if ... 如果……的話,將會(huì)(對(duì)某人)有幫助/好處. It helps if you can conquer your shyness and yell out English crazily. 如果你能夠克服你的羞澀,瘋狂大喊英語(yǔ),將會(huì)對(duì)你有好處. 164. It's amazing (that) ...……很了不起. It's amazing (that) China became the third country that launched a manned spacecraft. 中國(guó)成為第三個(gè)發(fā)送載人航天飛機(jī)的國(guó)家,真是很了不起. 165. It is/was...that/who... [強(qiáng)調(diào)句句型] It was Edward who told me about it. 告訴我這件事的是愛(ài)德華. 166. It is bad to....……是不好的. It is bad to push yourself too hard. Just try your best. 把自己逼得太緊不好.盡力而為就行了. 167. It's hard to imagine...…很難想像……. It's hard to imagine how he made it without any help. 很難想像沒(méi)有人幫助,他是怎樣成功的. 168. It is believed that...…人們認(rèn)為……. It is believed that what she said is true. 大家相信她的話是真的. 169. It didn't /won't take long before... 沒(méi)多久壞需要多久……就……. It didn't take long before he got used to life abroad. 沒(méi)多久他就適應(yīng)了國(guó)外的生活. 170. It is easier to... than to.......比.....容易. It is easier to buy a car than to keep one. 買車容易養(yǎng)車難. 171. It is easy enough to...……相當(dāng)容易. It is easy enough to copy and paste; but you should write something by yourself. 抄襲(復(fù)制十粘貼)非常容易,但是你應(yīng)該自己寫一些東西. 172.It is essential that... 有必要……. [主語(yǔ)從句使用虛擬語(yǔ)氣] It is essential that effective measures be taken to protect our civil rights. 有必要采取有效的措施來(lái)保障我們的公民權(quán)利. 173. It is good manners to do...……是有禮貌的表現(xiàn). It is good manners to bring along a small gift or some flowers when you are invited to dinner by a foreign friend. 如果外國(guó)友人邀請(qǐng)你共進(jìn)晚餐,去的時(shí)候帶上一份小禮物或者鮮花是有禮貌的表現(xiàn). 174. It is high time ... 現(xiàn)在是……的時(shí)候了./早就應(yīng)該……了. [從句使用虛擬語(yǔ)氣] It is high time we stopped talking about this silly question. 我們?cè)缇驮摻Y(jié)束討論這個(gè)愚蠢的問(wèn)題了. 175. It is hoped that... 希望……. It is hoped that no one was seriously injured in the car crash. 希望在這場(chǎng)車禍中沒(méi)有人受重傷. 176. It is important that... ……是很重要的. [主語(yǔ)從句使用虛擬語(yǔ)氣] It is important that something be done before it's too late. 在事情變得不能挽回之前采取一些行動(dòng)是很重要的. 177. It's long been my dream to...……一直是我的夢(mèng)想. It's long been my dream to make a speech in English. 用英語(yǔ)發(fā)表演講一直是我的夢(mèng)想. 178. It is (very /not) likely that... (很/沒(méi))有可能……. It is likely that it will rain this afternoon. 今天下午很有可能下雨. 179. It is (not) necessary to...……是(沒(méi))有必要的. 1) I think it is necessary to look before you leap. 我覺(jué)得三思而后行是有必要的. 2) When invited, it is not necessary for you to bring anything with you. 去做客不一定非要帶禮物. 180. It is no use doing sth. 做某事是毫無(wú)用處的. It is no use talking without doing. 光說(shuō)不做是沒(méi)有用的. 181. It is not unusual for sb. to do... 某人做……不足為奇. It is not unusual for the British people to drink tea. 英國(guó)人喝茶不足為奇. 182. It is possible /impossible to...……是(不)可能的. It's impossible to predict the outcome of the game. 要預(yù)知比賽結(jié)果是不可能的. [ outcome n. 結(jié)果;成果] 1 83. It is dangerous to......危險(xiǎn). It is dangerous to explore the jungle with so many wild animals around. 在很多野獸出沒(méi)的叢林里探險(xiǎn)是危險(xiǎn)的. 184. It is (rather) common to do... ……(相當(dāng))普遍. It is rather common for women to hold important positions in companies now. 如今女性在公司擔(dān)任重要職位相當(dāng)普遍. 185. It is reported that...據(jù)說(shuō)……./據(jù)報(bào)導(dǎo)……. It is reported that the world famous football star will come to China next year. 據(jù)說(shuō)那位聞名世界的足球明星明年要來(lái)中國(guó). 186. lt is required that... 要求……. [主語(yǔ)從句使用虛擬語(yǔ)氣l It is required that every student (should) attend the meeting this afternoon. 要求每個(gè)學(xué)生都參加下午的大會(huì). 187. It is said that... 據(jù)說(shuō)……. It is said that Liu Xiang will come to our city soon. 據(jù)說(shuō)劉翔不久將來(lái)我市. 188. It is thought that... 人們認(rèn)為……. It is thought that man's ability to learn languages makes him different from the animals. 人們認(rèn)為人類的語(yǔ)言學(xué)習(xí)能力使其區(qū)別于動(dòng)物. 189. It is (not) true that... ……(不)是真的. It is true that city life is much more exciting than country life. 確實(shí),城市生活比鄉(xiāng)村生活更令人興奮. 190. It is (very) difficult to...……(非常)困難. It is very difficult to foretell what the world will be like in the future. 很難預(yù)測(cè)將來(lái)的世界會(huì)怎樣. [ foretell v. 預(yù)言;預(yù)測(cè)] 191. Ifs really a challenge for me to...……對(duì)我來(lái)說(shuō)確實(shí)是一個(gè)挑戰(zhàn). It's really a challenge for me to take this job, and I thin I will appreciate working with you. 做這份工作對(duì)我來(lái)說(shuō)確實(shí)是一個(gè)挑戰(zhàn),我想我會(huì)很高興和你們一起工作的. 192. It is (very) useful to...……很有用. It is very useful to recite English sentences and passages. 背誦英語(yǔ)句子和短文非常有用. 193. It is/ was obvious/clear that... 很明顯……. It is obvious / clear that she is terribly nervous on stage. 很明顯她在臺(tái)上非常緊張. 194. It seems / seemed that... 好像…….似乎……. It seemed that no one knew what had happened.似乎無(wú)人知道發(fā)生了什么事. 195. It sounds like ...…聽(tīng)起來(lái)好像……. It sounds like a good idea. 聽(tīng)起來(lái)這主意不錯(cuò). 196. It takes / took / will take sb. some time / money to do sth. 某人花/花了/將花多長(zhǎng)時(shí)間/多少錢做某事. It took me years of hard work to speak good English. 為了講一口流利的英語(yǔ),我花了多年時(shí)間刻苦操練. 197. It wasn't until…that... 直到……才……. It wasn't until yesterday that I got your letter. 我直到昨天才收到你的來(lái)信. 198.It would be wonderful if... 如果……那就太好了. It would be wonderful if we can get together on Christmas. 如果圣誕節(jié)我們能聚一聚那就太好了. 199. It's not /just like sb. to do sth.……的行為不/正像某人的一貫作風(fēng). lt's not like Jim to be late for class. He regards time as the most important thing in life. 上課遲到不像吉姆的一貫作風(fēng),他把時(shí)間看作是生命中最重要的. 200. lt's a bad habit to...……是一個(gè)壞習(xí)慣. It's a bad habit to put off things until the last minute. 把事情拖到最后一刻才做是個(gè)壞習(xí)慣.

90. I think this is a good chance for you to... 我認(rèn)為這是你…;-的一個(gè)好機(jī)會(huì). I think this is a good chance for you to test your English. 我認(rèn)為這是測(cè)試你英語(yǔ)的一個(gè)好機(jī)會(huì). 91. I think it is a good idea to... 我認(rèn)為……是個(gè)好主意. I think it is a good idea to do exercise every day. 我認(rèn)為每天做運(yùn)動(dòng)是個(gè)好主意. 92. I think it is a waste of money / time doing... 我覺(jué)得……是浪費(fèi)樹(shù)時(shí)間. I think it is a waste of time sitting in front of the television all day. 我覺(jué)得整天看電視是浪費(fèi)時(shí)間. 93 .I think it's wrong to...我認(rèn)為……是不對(duì)的. I think it's wrong to impose your thoughts on others. 我認(rèn)為把自己的想法強(qiáng)加給別人是不對(duì)的. [impose v. 強(qiáng)加;利用] 94. I think that it is impossible to... 我覺(jué)得……是不可能的. I think that it is impossible to be there before eight. 我覺(jué)得在8點(diǎn)之前趕到那里是不可能的. 95. I think you might like to...我想你可能會(huì)喜,燈想……. I think you might like to know something about the new album. 我想你可能會(huì)想知道一些關(guān)于這張新專輯的介紹. 96. I think you'd better... 我覺(jué)得你最好……. I think you'd better hurry up, or you will be late. 我覺(jué)得你最好快點(diǎn),要不就遲到了. 97. I want to express my gratitude to... 我要感謝……. I want to express my gratitude to my family for their support. 我要感謝我的家人給我的支持. 98. I was impressed by... 我被……打動(dòng)了./……給我留下深刻印象. I was impressed by his inspiring words, and I decided to cooperate with him. 他令人鼓舞的話打動(dòng)了我,我決定跟他合作. 99. 1 wonder / was wondering if... 我想知道…….我在想是否……. 1) I wonder if I could take this dictionary home. 我想知道我能否把這本字典帶回家. 2) I was wondering if you'd like to go to a concert tomorrow night. 我在想你明天晚上是否愿意去聽(tīng)演唱會(huì). 100. I demanded (that)...我要求……. [賓語(yǔ)從句虛擬語(yǔ)氣] I demanded (that) I see the principal right away. 我要求馬上見(jiàn)校長(zhǎng).

51. I am very pleased to have this opportunity to... 我很高興有機(jī)會(huì)……. I am very pleased to have this opportunity to stand here and give you a speech. 我很高興有機(jī)會(huì)站在這里為你們演講. 52. I apologize for... 我為……道歉. I apologize for leaving you alone. 很抱歉把你一個(gè)人留下. 53. I believe (that)... …我相信……. I believe that we can conquer cancer totally some day. 我相信我們總有一天能夠完全戰(zhàn)勝癌癥. 54. I believe we should... 我認(rèn)為我們應(yīng)該……. I believe we should work together to protect our environment. 我認(rèn)為我們應(yīng)該攜手保護(hù)環(huán)境. 55. I can't imagine... 我無(wú)法想像……. I can't imagine what my life would be like if I were disabled. 我無(wú)法想像如果我身患?xì)埣?我的生活會(huì)怎樣. 56. I can't stand it when... 我無(wú)法忍受……. I can't stand it when people talk with their mouth full. 我無(wú)法忍受別人說(shuō)話的時(shí)候滿嘴食物. 57.I didn't expect to...我沒(méi)想到……. I didn't expect to receive such a pretty card from him. 我沒(méi)想到能收到他寄來(lái)的那么漂亮的卡片. 58. I didn't mean to... 我不是有意……. I didn't mean to offend you. 我不是有意要冒犯你的. [offend n.冒犯;得罪] 59. I didn't realize... 我不知道…….俄沒(méi)意識(shí)到……. I didn't realize how much this meant to you. 我沒(méi)意識(shí)到這對(duì)你意義有多大. 60. I (don't) feel like... 我(不)想……. 1) I feel like going rock climbing with you this weekend. 這周末我想和你一起去攀巖. 2) I really don't feel like going to the movies tonight. 我今晚真的不想去看電影. 61 . I don't get very excited about... 我對(duì)……不怎么感興趣. I don't get very excited about going to the concert. 我對(duì)去聽(tīng)演唱會(huì)不怎么感興趣. 62. I don't know how to... 我不知道如何……. I don't know how to answer the question. 我不知道如何回答這個(gè)問(wèn)題. 63. I don't see (that)... 我看不出…….我認(rèn)為……不……. I don't see (that) she really intends to help us out. 我覺(jué)得她并不打算幫助我們. 64. I don't think it is necessary to... 我認(rèn)為沒(méi)有必要……. I don't think it is necessary to leave so early.我認(rèn)為沒(méi)有必要這么早走. 65. I don't think it's right to... 我認(rèn)為……是不對(duì)的. I don't think it's right to bad mouth other people. 我認(rèn)為說(shuō)別人壞話是不對(duì)的. 66. I doubt that /if /whether... 我懷疑哦不相信……. I doubt if what he said is true. 我不相信他所說(shuō)的是真的. 67.I dream of... 我夢(mèng)想……. I dream of being a successful salesman. 我夢(mèng)想成為一名成功的推銷員. 68. I'm dying to... 我渴望…….俄盼望……. I'm dying to leave for Beijing to meet my parents. 我盼望著去北京見(jiàn)我的父母. 69. I feel very honored to... 我覺(jué)得很榮幸……. I feel very honored to be a member of this team. 能成為這個(gè)隊(duì)的一員我深感榮幸. 70. I'm fed up with... 我厭倦了…….我受夠了……. I'm fed up with all these traffic jams. 我討厭老是交通堵塞. 71. I'm sick and tired of... 我對(duì)……感到厭煩. I'm sick and tired of the same old routine every day. 我對(duì)每天同樣的呆板的日常生活感到厭倦. [routine n.日常事物;常規(guī)] 72. I find it hard for me to... 我發(fā)現(xiàn)……對(duì)我來(lái)說(shuō)很難. I find it hard for me to make a speech in public. 我發(fā)現(xiàn)在公眾場(chǎng)合作演講對(duì)我來(lái)說(shuō)很難. 73. I hate to disagree with you, but... 我不想跟你有不同意見(jiàn),但是……. I hate to disagree with you, but | think your view is impractical. 我不想跟你有不同意見(jiàn),但我認(rèn)為你的觀點(diǎn)不切合實(shí)際. [impractical adj.不切實(shí)際的] 74.I have confidence in... 我相信…….俄對(duì)……有信心. I have confidence in winning the Crazy English speech contest. 我有信心贏得這次瘋狂英語(yǔ)演講比賽. 75. I have nothing to do with... 我與……無(wú)關(guān). I have nothing to do with that man; I've never seen him before. 我與那個(gè)人一點(diǎn)關(guān)系都沒(méi)有,我以前從來(lái)沒(méi)見(jiàn)過(guò)他. 76. I have no experience in... 我在……方面沒(méi)有經(jīng)驗(yàn). I have no experience in dealing with children.我在和孩子打交道方面沒(méi)有什么經(jīng)驗(yàn). 77. I haven't (done)... for a long time. 我很久沒(méi)有……了. I haven't played the piano for a long time.我芫妹揮械?智倭? 78. I insist that... 我堅(jiān)決要求……. [賓語(yǔ)從句使用虛擬語(yǔ)氣]│ I insist that you give me my money back.我堅(jiān)持要求你把錢退給我. 79. I insist on (doing)...…我堅(jiān)持……. I insisted on making him our coach. 我堅(jiān)持要他做我們的教練. 80. I intend to...…我打算……. I intend to give him a surprise. 我打算給他一個(gè)驚喜. 81. I like nothing better than... 我喜歡……勝過(guò)任何東西.俄最喜歡……. I like nothing better than helping people. 我最喜歡幫助別人. 82. I never dreamed of...…我從未想過(guò)……. I never dreamed of meeting you here. What a coincidence! 我從未想過(guò)會(huì)在這里見(jiàn)到你.真是太巧了! [coincidence n.巧合;湊巧] 83. I prefer... to...…我喜歡……甚于……. I prefer working as a manager in a small company to working as a clerk in a big one. 我喜歡當(dāng)個(gè)小公司的經(jīng)理甚于在大公司做小職員. 84. I prefer to... rather than...我寧愿…...而不愿.…". I prefer to stay at home rather than go out 我寧愿呆在家里而不愿出去. 85. I really want to know... 我真的很想知道……. I really want to know how to improve my English pronunciation. 我真的很想知道如何改進(jìn)我的英文發(fā)音. 86. I set my mind to do sth. / on sth.我下定決心……. I set my mind to believe, hope, and endure all things. 我下定決心對(duì)所有事情采取信任,希望和容忍的態(tài)度. 87. I sincerely hope that...我真誠(chéng)地希望……. I sincerely hope that our friendship will last forever. 我真誠(chéng)地希望我們的友誼天長(zhǎng)地久. 88. I strongly advise you to... 我強(qiáng)烈建議你……. I strongly advise you to attend the Crazy English Summer Camp, and I'm sure you will get more than you expected. 我強(qiáng)烈建議你參加瘋狂英語(yǔ)夏令營(yíng),我相信你的收獲會(huì)比你想像的要多. 89. I suggest (that)... 我建議……. [賓語(yǔ)從句使用虛擬語(yǔ)氣1 I suggest (that) you go there by yourself. 我建議你自己

2、講述電表改裝時(shí)，要抓住問(wèn)題的癥結(jié)所在，即表頭內(nèi)線圈允許通過(guò)的最大電流是有限制的(滿偏電流Ig)，那么要測(cè)量較大的電壓(或電流)怎么辦？通過(guò)啟發(fā)引導(dǎo)，學(xué)生能夠提出電阻分壓(或分流)，然后讓學(xué)生討論，推導(dǎo)出有關(guān)公式。教材結(jié)合具體例題，分別推出了分壓電阻公式R＝URRg／Ug和分流電阻公式R＝IgRg／IR。