Question

It was not until dark___he found____he thought was the correct way to solve the problem.

A that;whatB that;thatC when;whatD when;that答案加原因

Answer 1

选A。
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。

Answer 2

A,that: It it not until...that... “直到...才”what: what he thought “他所想的”句意：直到天黑，他才发觉他刚才所想的解决问题的方法是正确的。

Answer 3

答案A
第一个选that引导的主语从句，是真正的主语，it只是形式主语。
第二个引导宾语从句what在从句中做主语

Answer 4

A
第一个是强调句型 所以用that
第二个宾语从句what在从句中做主语 其实是waht （he thought） was the⋯⋯括号中是插入语