1 .
1. You__________________ go on working because you look so tired now.
2. Li Hua__________________pass an examination before he can start work.
3. You__________________come to the meeting if you’re too busy.
4. You__________________play now! You shall finish your homework first!
5. I know things are hard with you, but you__________________try to get over the difficulties.
6. I didn’t see her at the meeting this morning; she__________________have spoken at the meeting.
7. You__________________imagine what difficulty we had walking home in the snowstorm.
8. The weather turned out to be fine yesterday. I __________________have taken the trouble to carry my umbrella with me.
9. You__________________follow the doctor’s advice. I think it will do good to you.
10. I__________________have phoned Ed this morning，but I forgot.