三、一般过去时

一般过去时主要表示过去某一时刻发生的动作或情况，句中通常有表示过去某一时刻的状语，如：

Oberlin College degrees to both sexes in 1837, but coeducation in american colleges did not spread until the second half of the century.

A) awarded B)awards

C) awarding D)awarded

A 为正确答案。本句显然是谈论过去的事情，且句中有表示过去的状语“in 1837”。

The operetta (小歌剧) first as a popular form of musical theater in the nineteenth century.

A) to emerge B) emerging

1. has emerged D) emerged

2. 为正确答案。注意句中表示过去某一刻的时间状语 in the nineteenth

   century.