Question

There was ______ time _____ Chinese used foreign oil.

A．/; when

B．a; while

C．a; when

D．/; while

Answer 1

C

试题分析：句意：有一段时间中国人使用外国的油。there was a time 历史上有一段时期。time 后接定语从句用关系副词when作连接词在从句中作时间状语。故选C。