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
A
题目分析:句意:直到天黑他才发现他想到的是解决问题的正确的方法。第一空填that,这是强调句,It was not until that…,第二空填what,在found后面的宾语从句中,what he thought是主语从句,主语从句中缺少主语,用what引导主语从句,选A。