Question

【题目】It was quite a serious mistake, _______ caused by carelessness.

A.which I think wasB.I think which was

C.which I think it wasD.I think which it was

Answer 1

【答案】A

【解析】

句意：这是一个相当 严重的错误，我认为是粗心大意造成的。

考查定语从句。本句是非限制性定语从句，先行词mistake是物，故用which引导此定语从句，I think是插入语，放在which的后面，故选A。