Ⅰ. 单句语法填空
1. Every few years, the coal workers have (have) their lungs X-rayed to ensure their health.
2. I know a little about Thailand, as I went (go) there three years ago.
3. Hurry up, kids! The school bus is waiting (wait) for us!
4. —What time is it?
—I have no idea. But just a minute, I will check (check) it for you.
5. —Dr. Jackson is not in the office at the moment.
—All right. I will call (call) him later.
6. The real reason why prices were (be), and still are, too high is complex, and no short discussion can satisfactorily explain this problem.
7. He has learnt (learn) English since he was 6 years old.
8. —Is Peter coming?
— No, he changed (change) his mind after a phone call at the last minute.
