請看下面的題，答句是個什麼從句？
“What were you trying to prove to the police？” “_________ I was last night.”
A. That B. When C. Where D. What
【分析】此題應選 C，其餘三項均有可能誤選，答句為省略句，其完整形式為 I was trying to prove to the police where I was last night. (where 引導的是一個賓語從句)。請看以下類似試題：
(1) “What made her so happy？” “_________ her son passed the college entrance examinations.”
A. That B. 不填 C. Since D. For
【分析】此題選A，為That her son passed the college entrance examinations made her so happy. 之省略。
(2) “What did she tell you？” “_________ she would be late”
A. That B. When C. Where D. Whether
【分析】此題選A，為 She told me that would be late. 之省略。
(3) “What did he ask you？” “_________ I would be late.”
A. That B. When C. Where D. Whether
【分析】此題選D，為 He asked me whether I would be late. 之省略。
類似地，下面一句是非謂語動詞作主語：
(4) “What made you so upset？” “_________ my wallet.”
A. Lost B. Losing C. Having lost D. Being lost
【分析】此題選B，為 Losing my wallet made me so upset. 之省略。
