l was worried about ___it was safe A.what B.that C.if D.whether
问题描述：
l was worried about ___it was safe A.what B.that C.if D.whether
答案为什么是D而不是C?
答
D.
句意：我担心它是否安全.
后面从句是一个完整句子,不缺少成分,排除what和that.if 和whether都可引导宾语从句,但是whether及其引导的成分可放于介词之后,作介词的宾语,if不能.此时whether引导的句子充当介词about的宾语,不能用if.
所以,答案D.
希望回答对你有所帮助!也就是说if不能做介词的宾语吗？？是的，呵呵