At one school for sailors, the swimming instructor was very good.He had never failed to teach anybody to swim by the time the course ended.One year, however, 14 was one particular boy on the training course 15 seemed quite unable to learn to swim.The instructor tried giving him extra lessons, but he had 16 success at all, whatever he did.In the end, as the time drew near for the course to end, he had to admit defeat.

　　One day, he called the boy aside after the swimming lesson and said 17 him “ John, I have tried very hard to teach you to swim,but I have failed 18 the first time in my life.Now, I want to give you a piece of 19 . Listen carefully.”“Yes, sir,” answered the boy. “Well,”the instructor went on, “if you are ever in a ship and it sinks, just jump over the side into the sea, go right down to the bottom and run to the shore as 20 as you can. That is the only way you will save your life.”

　　11. A.do

　　B.teach

　　C.finish

　　D.watch

　　答案：A

　　[解析]根據(jù)上下文前面說(shuō)到孩子們學(xué)習(xí)數(shù)學(xué)和科學(xué)以及學(xué)習(xí)怎樣系鞋帶，因此后面應(yīng)該是填do, 做其它的一些實(shí)踐活動(dòng)。

　　12.A. learned

　　B.studied

　　C.done

　　D.taught

　　答案：D

　　[解析]根據(jù)上下文判斷，這句話的意思是：其中最重要的是教給孩子怎樣游泳。