14．(坐標系與參數(shù)方程選做題)在極坐標系中，直線l的方程為ρsinθ=3，則點(2，π/6)到直線l的距離為　　　　　　 ．

[解析]法1:畫出極坐標系易得答案2; 法2:化成直角方程及直角坐標可得答案2.

　 15．(幾何證明選講選做題)如圖4所示，圓O的直徑AB=6，C為圓周上一點，BC=3過C作圓的切線l，過A作l的垂線AD，垂足為D， 則∠DAC=　　　　 ．

[解析]由某定理可知,又,

故.

(2007海南、寧夏)

15．幾何證明選講選做題］如圖所示，圓O的直徑為6，C為圓周上一點。BC＝3，過C作圓的切線l，過A作l的垂線AD，垂足為D，則∠DAC＝______；線段AE的長為_______。

答案：；3。

解析：根據(jù)弦切角等于夾弧所對的圓周角及直角三角形兩銳角互余，很容易得到答案； AE=EC=BC=3；

(2007廣東文)

14．(不等式選講選做題)設(shè)函數(shù)則=_____；若，則x的取值范圍是________；

答案：6；

13．(坐標系與參數(shù)方程選做題)在平面直角坐標系xOy 中，直線l的參數(shù)方程為(參數(shù)t∈R)，圓C的參數(shù)方程為(參數(shù))，則圓C的圓心坐標為_______，圓心到直線l的距離為______.

答案：(0，2)；.

解析：直線的方程為x+y-6=0，d=;

70、Can you work out what these squiggles mean?

答案：68、事情的結(jié)果很不錯。69、我一向無法了解她。70、你能辨認出這些潦草的字跡是什么意思嗎？

69、I've never been able to work her out. ________________

(1)　　　 We must work out a plan as quickly as we can.<制定，擬定，定出>

(2)　　　 Have you worked out this problem yet?<算出，估計出>

(3)　　　 I can't work out the meaning of the poem.<理解，弄懂，看出>

(4)　　　 This map is wrong；I can't work out where we are.<判斷，說出，看出>

(5)　　　 Things will work out if you will just be patient.<得到圓滿解決>

(6)　　　 Things have worked out badly.<(情況等)結(jié)果是>

(題組訓練)英譯漢：

68、Things worked out quite well. ________________

(1)　　　 The assistant did not take her seriously and advised her to buy two bottles of very expensive wine.<認真對待>

(2)　　　 He led the ships down the river to a place where the British army could land safely and take the enemy by surprise.<突然襲擊>

(3)　　　 I won't take up much of your time.<占去(時間)>

(4)　　　 The table takes up too much room.<占去，占據(jù)(空間)>

(5)　　　 When he left school he took up journalism.<從事某項活動，發(fā)展某種愛好>

(6)　　　 People should be ready to go to prison for their beliefs，but they should never take up anus to fight.<拿起武器>

(7)　　　 When you return to the office the following morning or after the holiday，you can listen to the messages and take any necessary action.<采取必要的行動>

(8)　　　 The teacher took up the lesson where he left off yesterday.<繼續(xù)講述>

(9)　　　 Jean took advantage of the lunch hour to finish her homework.<利用>

(10)　 I take back what I said.<收回>

(11)　 Take it easy.The roads are icy.<不要著急>

(12)　 He is taking over my job while I am on holiday.<接替，接管>

(13)　 He seemed to take great pride in his work.<對……感到驕傲>

(14)　 She had taken the trouble to buy the books for me.<費力，不怕麻煩>

(15)　 I'll take on the work，but I can't tell you exactly when I'll finish it.<從事>

(16)　 The Great Wall has taken on a new look since the liberation.<呈現(xiàn)>

(17)　 Is the supermarket taking on any more assistants?<雇用>

67、If you don't know the words，you can ________________ (refer to)a dictionary.

答案：65、turned up 66、turned down 67、turn to

66、His invitation is ________________ (refused).