Подчеркните правильный вариант модального глагола в следующих предложениях: 1. must/can i have a biscuit please, mum? 2. may/can you see anything in this inky darkness? 3. he must/can work systematically if he wants to know french well. 4. must/may i borrow these files for a moment, sir. 5. have to/may i come in? 6. he can/must not speak english yet. 7. i will be able to/can pass my exam.