Step Ⅲ.Drill

就 must always 和 must never 进行下列操练： T：You must do your exercises carefully. Ss：You must always do your exercises carefully. T：You must listen carefully in the class.

Ss：You must always listen cary fully in the class. T：You mustn’t be late.

Ss：You must never be late. T：You mustn’t play on the road.

Ss：You must never play on the road.

（ You must come before classes begin./You must help the old people./You mustn’t draw on the walls. You mustn’t play all games in the classroom. etc）