Question

【题目】They overcame some difficulties and completed the work ahead of time, ________ was something we had not expected.

A.thatB.which

C.itD.what

Answer 1

【答案】B

【解析】

考查定语从句。句意：他们克服了一些困难，提前完成了工作，这是我们没有预料到的。此句的先行词为前面的整个句子，指“他们克服了一些困难，提前完成了工作”这件事，从句缺少主语，指物，应该用which。故选B。