Question

【题目】Silk___________ one of the primary goods traded along the Silk Road by about 100 BC.

A. had become B. was becoming

C. has become D. is becoming

Answer 1

【答案】A

【解析】考查过去完成时。句意:到大约公元前100年,丝绸已经成为丝绸之路上最主要的交易商品之一。根据句意及by about 100 BC可知,become的动作发生在过去的过去,故选过去完成时。