23. Having checked the doors were closed, and ______ all the lights were off, the boy opened the door to his bedroom. (2007湖南)

A. why　　　　 B. that　　　　 C. when　　　　 D. where

[解析] B 所填选项引导宾语从句，从句中不缺任何成份和意义，只缺少连接词，所以用that引导。

22. It is none of your business 　　　　other people think about you. Believe yourself. (2007 福建)

A. how　　 　　 B. what 　　　 　　 C. which　　　　　　　 D. when

[解析] B 该句中it作形式主语，what引导主语从句。该主语从句还原为疑问句应为“What do other people think about you?”。

21. Why not try your luck downtown, Bob? That’s ______ the best jobs are. (2007浙江)

A. where　　　　 B. what　　　　 C. when　　　 D. why

[解析] A That’s后为表语从句，此处where与downtown相呼应，根据句意可排除其他选项。

20. Choosing the right dictionary depends on ______ you want to use it for. (2007江苏)

A. what　　 B. why　　 　　 C. how　 　　　 D. whether

[解析] A on后为宾语从句，此处用what引导宾语从句，在从句中充当介词for的宾语。

19. ______ he referred to in his article was unknown to the general reader. (2007上海)

A. That　 　 B. What　　 　　　 C. Whether　　 　　　 D. Where

[解析] B所填选项引导主语从句，且在从句中充当宾语，所以用what引导。

18. The seaside here draws a lot of tourists every summer. Warm sunshine and soft sands make ________ it is. (2007天津)

A. what　　 　B. which　　　 C. how　　　　 D. where

[解析] A 此处用what引导宾语从句，在从句中充当表语。which引导宾语从句时意为“哪一个”，表示选择；how引导宾语从句时意为“如何”；where引导宾语从句时意为“在……地方”，均与句意不符。

17. He didn’t make ______ clear when and where the meeting would be held. (2007天津)

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

[解析] C 此处用it作形式宾语，when and where the meeting would be held作真正的宾语。当复合宾语中的宾语是从句时，一般用先行代词it作形式宾语，而将从句放在补语的后面。

16. ____ matters most in learning English is enough practice. (2007全国II)

A. What　 　　　 B. Why　　　 　　 C. Where　　　 　　 D. Which

[解析] A所填选项引导主语从句，且在从句中充当主语，所以用what引导。

15. Could I speak to______ is in charge of International Sales, please? (2007山东)

A. anyone　　　 B. someone　　 C. whoever　　　 D. no matter who

[解析] C to后为宾语从句，此处用whoever引导宾语从句，在从句中充当主语，此时whoever=anyone who；no matter who只能用于引导让步状语从句。

14. ______ we are sure about is the need to prevent children from being spoiled. (2008上海春招)

A. What　　　　　　　 　 B. Which　　　　　　　 C. Whether　　　　　　　 D. That

[解析] A 所填选项引导主语从句，且在从句中充当介词about的宾语，所以用what引导。