Question

By the time we got there, the meeting _____.

A. was beginning B. had began
C. had already begun D. begun

Answer 1

C
by the time是明显的完成时的标志，从句中用的是got过去时，因此主句应该用过去完成时。只能在BC中选，但Bhad后的begin应该用过去分词形式，所以选C

Answer 2

C 过去完成时 (因为在到达之前发生的动作)

Answer 3

选C
翻译：我们到那时，会议已经开始了。
从句中又By the time, 主句用完成时。
从句we got there，主句往前推一个时态——用过去完成时。

Answer 4

C. had already begun