she has to be in bed by ten.（对划线部分提问）答案是when does she have to be in bed我这么写行吗?
问题描述：
she has to be in bed by ten.（对划线部分提问）答案是when does she have to be in bed我这么写行吗?
what time does she have to be in bed
答
不行.因为what time 只能表示一个具体的时间点.
而原句中的by ten 是“十点之前”,是一个时间段,非时间点,故不能用what time 提问,必须用when.
学习是一件愉快的事! (*^__^*)
请及时采纳,多谢!