4. Was it in this palace           the last emperor died ?

A. that       B. in which          C. in where            D. which

〖答案與簡析〗選A。測試it 用在強調結構中，為了強調句子的某一成分（通常是主語、賓語或狀語），常用強調It is (was) + 被強調成分 + that(或who）…。被強調部分指人時用 that 或 who ，在其它情況下（包括強調時間或地點狀語）用that 。又如：

1）Was it during the Second World War            he died ? (MET 88）

     A. that             B. which        C. in which            D. then

2) It was not            she took off her dark glasses            I realized  she was a famous film star .

     A. when ; that  B. Until ; that              C. until ; when       D.  when ; then

答案 1) A  2) B。

3. I don't think              possible to master a foreign language without much memory work .

A. this B. that   C. its     D. it

〖答案與簡析〗選D。測試 it 用作形式賓語，代替由不定式、動名詞或從句表示的真正賓語。當賓語有自己的補足語時，用it作形式賓語，真正賓語放在補足語之后。常用這種句型的動詞有think , make ,  find , feel , consider 等。

2. Is               necessary to tell his father everything ?

     A. it         B. that            C. what         D. he

〖答案與簡析〗選A。測試 it 用作形式主語，代替由不定式（或不定式復合結構）、動名詞或從句表示的真正主語。又如：

1）Is               possible to fly to the moon in a spaceship ?

     A. now            B. man           C. that            D. it

2）Is               necessary to complete the design before National Day ?

     A. this             B. that            C. he              D. it

3）Does           matter if he can't finish the job on time ?

     A. this             B. that            C. he              D. it

4）It worried a bit          her hair was turning grey .

     A. while          B. that            C. if D. for

答案1） ―  4）DDDB。

1. Tom's mother kept telling him that he should work harder , but           didn't help .

    A. he          B. which           C. she          D. it

〖答案與簡析〗選D。測試 it 用作人稱代詞，代替前文提到過的事物。又如：

1）― The light in the office is still on.

     ― Oh , I forgot            .

     A.  turning it off     B. turn it off     C. to turn it off    D. having turned it off

2）― Have you heard the news about Tom ?

  ― No , what          ?

     A. is it           B. it is          C. are they      D. they are

3）If you don't know the word , why don't you             in the dictionary ?

     A. look at it       B. look after it       C. look up it       D. look it up

答案1）― 3）CAD。值得注意的是，由動詞和副詞組成的短語動詞用it 作賓語時，it 應置于動詞和副詞之間。

2. it 代替連接代詞或連接副詞引導的從句作形式主語。

1) It is  known (not decided , not made clear ,  found out ,  discussed , being discussed , being considered , a question , uncertain等) + 連接代詞或連接副詞引導的從句。

It is still a question when we shall have our sports meet . 我們將什么時候舉行運動會還是一個問題。

It is uncertain whether he can attend this conference or not . 他能否來開會還不能確定。

2) It doesn't matter(doesn't  matter too much , doesn't make too much difference等) + 連接代詞或連接副詞引導的從句。如：

It doesn't matter whether we go together or separately . 我們一起去還是分開去都可以。

It doesn't matter too much to me what you do or where you go . 你做什么或去什么地方，對我都無關緊要。

【動腦動手】

單元能力立體檢測

1. it 代替連詞 that 引導的從句作形式主語。

1) it + be + 過去分詞 + that 從句

It's said that Tom has come back from abroad . 據(jù)說湯姆已經(jīng)從國外回來了。

It was reported that dozens of  children died in the accident . 據(jù)報導，數(shù)十名兒童在事故中死亡。

可用于該句型的過去分詞還有：known , thought , told , believed , hoped , announced ,expected , decided , suggested等，該句型常可以轉換成含有賓語從句的復合句或者含有不定式作主補的簡單句。如：

 It's said that Tom has come back from abroad . →People say that Tom has come back from abroad . →He is said to have come back from abroad .

2) It + be + 名詞詞組 + that 從句

It's a pity that he can't swim for his age . 真遺憾，就他的年齡來講，他竟不會游泳。

It's a wonder that you could finish such a hard task in such a short time . 真奇怪，你竟能在如此短的時間內完成艱巨的任務。

可用于該句型的名詞詞組還有：an honour , a good thing , a fact , a surprise , good news等。

3) It + be /seem + 形容詞 + that 從句

It is likely that they will beat us tonight .今晚很可能他們會贏我們。

It doesn't seem that she will give us a hand .她幫我們的可能性似乎不太大。

可用于此句型的開容詞還有；wonderful , true , good , right , wrong , (un)important ,useless , surprising , clear , possible , unusual , lucky , certain 等。

4) It + seem / appear / happen + that 從句

It seems that he enjoys pop songs very much .看來他非常喜歡流行歌曲。

It appears that Tom might change his mind .看來湯姆會改變主意。

It happened that I went out that day .碰巧我那天外出了。

注意，句型4可轉換成含不定式的簡單句。如上述句子可轉換為：

He seems to enjoy pop music very much . / Tom appears to change his mind ./ I happened to go out that day.

6.  It / This / That + the first(second , third …) time + that-clause

這個句型表示截止到說話時為止的某人的一種經(jīng)歷，關鍵是注意time前有序數(shù)詞，主句是 is 時 ，從句要用現(xiàn)在完成時；如果主句用一般過去時was ，則從句須相應地用過去完成時。例如：

This is the first time (that) these Europeans have visited the Great Wall .

It was the fifth time (that) I had paid a friendly visit to Africa .

二、It代替從句作形式主語的常見句型

5.   It + be + time +  that-clause

這個句型屬虛擬語氣結構，不管主句中用的是 is 或 was ，that從句都須用動詞的過去式或should + 動詞原型(但不及用過去式普通)，在time之前有時可加上high或about 以加強語氣。例如：

 It is time(that)we handed in our exercises .(= It is time that we should hand in our exercises .)

It is high time  (that ) she wrote a letter to her boyfriend .

4.  It + be + 時間 + that-clause

這個句型是個強調句型。例如：

It was two years ago that he made an important invention .

(原句是：He made an important invention two years ago . )

It was at 5 o'clock that he practised playing the violin in the morning .

(原句是：He practised playing the violin at 5 o'clock in the morning . )

比較：It was 5 o'clock when he started in the morning .

(5 o'clock前沒有介詞，這是個定語從句)

3.  It + be + 時間 + when-clause

這個句型中, it 指時間，而且表示時間的詞語前沒有介詞(時間一般為具體時間)。主句中的謂語動詞和從句中的謂語動詞在時態(tài)上一般是一致的，主句是will be，when從句用一般現(xiàn)在時代替將來時。例如：

It was already 8 o'clock when we got home .

It was the next morning when we finished our work .

It will be midnight when they get there .