Ответ: 1. You must be tired: you have been working for hours. 2. He may have visited
the Hermitage when he was in St Petersburg last year. 3. It must be
а very deep lake. 4. That building in the distance may be the
station. 5. You can’t have lost you passport; you
may have put it into another bag. 6. The girl may have been frightened. 7. You may have left your textbook in the canteen. 8. They can’t give up such а brilliant idea. 9. You look pale. You may be
tired. 10. This boy can’t be а good friend.