What are they doing?用(a lesson) 回答
问题描述:
What are they doing?用(a lesson) 回答
What are they doing?用(a lesson)该怎么 回答
What must they do?用(a meal)回答
What must they do?用(a holiday)回答
答
They are having a lesson.
They must have a meal.
They must have a holiday.