根据句意,用所给的动词的适当形式填空。
Work harder, and you (get) better grades in your lessons.
—Come and have some cakes. —Thanks.I ________ (have) my lunch already.
When Andy came into the room, Millie (watch) TV.
What can you do ______________ (prevent) the water pollution?
My dad’s car (break) down because of the cold weather yesterday.