问题补充:
The reason their failure you know is they didn get fully prepared for the experiment.
A. why.., that
B. that.., why
C. for.., that
D. why.., because
答案:
A. why.., that
B. that.., why
(答案→)C. for.., that
D. why.., because
解析:此题关键是their failure为名词词组,A项why后须接句子。