—You know, Bob is a little slow_____understanding, so….—So I have to be patient _____him.
13. — How do you keep fit?— By having a healthy diet and _________ regularly.
12. Having finished their morning work, the clerks stood up behind their desks, ________ themselves.
11. ________ no need for us to discuss the problem again. It has already been settled.
10. — How old are you, madam?— If you _______ know, I’m twice my son’s age.
9. We forbid _____ in the reading room. That is, you are forbidden _____ in the reading room.