they exercise two hours a week.对two提问 ()()()do they exercise a week?

问题描述:

they exercise two hours a week.对two提问 ()()()do they exercise a week?

At what frequency
这里句子是问频率,次数
他们每周练习多少时间
那么就2小时

(How)(many)(hours)do they exercise a week?

对two提问,三个空子填(How)(many)(hours)
对 two hours 提问,两个空子填(How)(long)