The reason _it has been raining for 5 days is _ the crops has been flooded.

问题描述:

The reason _it has been raining for 5 days is _ the crops has been flooded.
A.that;why
B.why;that
C.which;why
D.why;which
为啥

that引导同位语从句,
the reason的内容就是that后引导的内容.
整体结构是:The reason is why the crops has been flooded.
that it has been raining for 5 days (已经下了5天的雨是原因)