－What did your parents think about yourdecision? －They always let me doI think Ishould A.

问题补充：

－What did your parents think about yourdecision?

－They always let me doI think Ishould．

A. when

B. that

C. how

D. what

答案：

A. when

B. that

C. how

(答案→)D. what

解析：what I think I should(do)作do的宾语。句意为：他们总是让我做我认为我应该做的事情。