用括号内所给动词的正确形式填空。

1. Since he fell off the bike, John ______ (lie) in bed for nearly a week.

2. We've worked for a long time. Let's stop ______ (drink) some water.

3. You mustn't touch the machines unless you ______ (allow) to.

4. — What's his plan after he leaves school?

    — He ______ (go) to Beijing for further education.

5. — Has the teacher finished marking the exam papers? 

    — Sorry, I don't know. He ______ (mark) them in the office yesterday afternoon.