-Mr.brown went to Shanghai for the air exhibition last week.-Is that ___ he had two days off?

问题描述:

-Mr.brown went to Shanghai for the air exhibition last week.-Is that ___ he had two days off?
A.what B.when C.why

布朗先生上周去上海参观航空展览去了.
这就是已经两天找不到他的原因吗?
答案是 C