She double-checked her paper before handing it in [for fear that]there should be spelling mistakes.(为何不能用in case that)
He was about to tell me the secret[when] a bullet shot him dead.(为何不能用as)
Please send me [word] of your progress whenever it is convenient.(为何不能用the word)
While he[could]escape at that time, he didn't even make an attempt.(为何不能用managed to)
谢谢。