It was not until dark he found he thought was the correct way to solve the problemA. th

问题补充：

It was not until dark he found he thought was the correct way to solve the problem．

A. that; what

B. that; that

C. when; what

D. when; that

答案：

(答案→)A. that; what

B. that; that

C. when; what

D. when; that

解析：考查复杂句：第一空是not until 用于强调句，构成it is not until·····that “直到····才”

第二空后的he thought是插入语，将he thought删掉后会形成这样一个句子：he found was the correct way to solve the problem.句中的主语和谓语分别是he, found，因此横线上的词要引导一个宾语从句。分析宾语从句的句子成分就会发现，宾语从句的主语缺失，只能用what来充当主语，that在名词性从句中不充当成分。句意：直到天黑他才发现他所想的是解决问题的正确的方法。选A。