Измените следующие предложения, употребляя сочетания must или may с Indefinite или Perfect Infinitive:
1. They probably came home very late as I was asleep.
2. You probably walked very fast it you reached the station so quickly.
3. I cannot find my fountain-pen. I probably left if in the lecture-hall.
4. He is probably a very good student because his paper is excellent.
5. Perhaps he is in the library now.
6. He has probably left Moscow because he hasn't come to the lecture.
7. He probably knows English very well because there are no mistakes in his composition.

1. They must have come ... .
2. You must have walked ... .
3. I must have left it ... .
4. He must be a.very good student ... .
5. He may be ... .
6. He must have left Moscow ... .
7. He must know English ... .