1.—I fell sick!
--I think it is _______ you are doing too much.
A.why B. when C. what D. because
2. The reason why he hasn’t come is ___________.
A. because his mother is ill B. because of his mother’s being ill
C. that his mother is ill D. for his mother is ill
如题,如果第一题选D的话,为什么第二题不选A却选C?
这两个都是表语从句吧?