He goes to bed at nine o'clock 对 at nine o'clock提问
问题描述：
He goes to bed at nine o'clock 对 at nine o'clock提问
答
When does he go to bed?
what time does he go to bed?
答
When does he go to bed?
答
When does he go to bed?
What time does he go to bed?
俩种提问方式