Exercise 4 p. 116. Combine the verb must with the proper

Exercise 4 p. 116. Combine the verb must with the proper form of the infinitive in brackets.
1. Look! People are hurrying along the street with collars and umbrellas up. It must (to rain) hard. 2. Peggotty enclosed the half-guinea in the letter; I was afraid she must (to have) a world of trouble to get it out of Mr. Barkis's box. (CD.) 3. You must (to follow) my advice. There is no other way out for you. 4. I saw an old woman sleeping soundly in Green Park. A shower was falling at the time, she must (to be) drenched to the skin. (Ldn) 5. All time we were out the two gentlemen smoked incessantly which, I thought, if I might judge from the smell of their rough coats, they must (to do) ever since the coats had first come home from the tailor's. 6. "The hotels must (to do) a tremendous business," old Jolyon thought. "A few years ago there had been none of these big hotels." Then he thought of his son. "... If Jo were only with him. The boy must (to be) forty by now." (Gls.) 7. She must (to be) angry with you. She does not even look in your direction. 8. She must (to get) angry with me. She left without saying good-bye. 9. Mary must (to be) ill, otherwise she would have come. 10. Mary must (to fall) ill. She looked so pale and tired last night.