Question

The factory was built in a secret place, around _________ high mountains.

A．which was

B．it was

C．which were

D．them were

Answer 1

C

around which were high mountains 是一个由“介词+which”引出的非限制性定语从句，而在该从句中，主语是 high mountains，around which 是表语，所以句子谓语应用复数were，而不是用单数 was。