(单选题)

______ that it was so difficult to apply for this opportunity, I wouldn’t have wasted much time preparing relative materials.

A.Had I known

B.If I should know

C.Have I known

D.Did I know

参考答案：A

参考解析：

考查省略if，had提前的用法。句意：如果我知道申请这个机会如此困难，我就不会浪费时间准备相关材料了。分析句意可知，此处表示对过去的虚拟，从句部分补充完整应该是：If I had known that it was so difficult to apply for this opportunity。在虚拟条件句中，若从句中出现了were、had和should，虚拟条件从句中可以将were、had和should提前至句首，并省略if。故选A。

知识点：虚拟语气英语专业基础知识英语语法教师招聘-小学英语