Question

I don't remember how many years ago ___ that people began to grow crops.

A.it was when B.was it that C.it was that D.was it when
请解答，要有解析，谢谢。

Answer 1

C 强调句型 强调的是 how many years ago

Answer 2

C
这是同位语强调句，我不清楚那些人多少年前开始种庄稼。
强调是那些人种庄稼，而不是别人。