请看下面这道题，是all all？还是both both？还是that that？或还是which which？

He told us __________ he had seen in the accident.

A. all all                         B. both both                     C. that that                     D. which which

此题应选A。容易误选C。误认为第一个that用作宾语从句的引导词，第二个that在宾语从句中用作seen的宾语。

大家知道：引导名词性从句(主语从句、宾语从句、表语从句、同位语从句等)的that 在句中是不能充当任何句子成分的。所以若选C，将第二个that看作是宾语从句中谓语动词seen的宾语，这是不成立的。

正确的分析是：此题应选A，第一个all用作us的同位语，第二个all用作动词 told 的直接宾语，其后的 that he had seen in the accident是用以修饰第二个all的定语从句，全句意为：他告诉我们所有的人他在事故所看到的所有情况。

有时命题者故意将几个比较特殊的句子结构，通过某种特殊手段混在一起，主要考查考生对句子结构的综合理解能力。请做以下试题(注意分析句子结构)。如：

1. Would you tell me what subject you were good_________ school?

A. at at                          B. in in                        C. for for                    D. with with

2. The books we _________ nothing to do with this subject.

A. have have                  B. do do                      C. read read                 D. need need

3. Whoever has a strong __________ not leave his work halfway done.

A. shall shall                   B. will will                   C. can can                   D. may may

答案：1. A 2. A 3. B