I can’t understand the boy alone.A. why did she leaveB. why had she leftC. why she leftD

问题补充：

I can’t understand the boy alone.

A. why did she leave

B. why had she left

C. why she left

D. why she had left

答案：

A. why did she leave

B. why had she left

(答案→)C. why she left

D. why she had left

解析：句意:我不明白她为什么把那个男孩一个人留下。这里why 引导的是一个宾语从句，我们知道宾语从句中应该用陈述语序，故我们可以排除A、B两项；根据句意可知她把那个男孩一个人留下是一件过去的事情，应该用一般过去时，故选C。D选项使用的是过去完成时，表示过去的过去，不符合句意。