1.Andy really didn't know ( ) to help the dying old woman.
A.what to do B.whether he can do
2.I don't know when she( ),but when she( ),I will let you know.
A.arrive,will arrive B.will arrive,arrives C.arrives,arrives D.will arrive,will arrive
3.I can't understand ( ) the boy alone.
A.why she left B.why she had left
可以排除的选项我去掉了,没有打出来,但剩下的选项我都不知道应该选谁,为什么?错的错在哪?请高手帮忙解析下这三道题,清楚的话我一定加分,谢谢!
参考资料:英语牛人团