11. — Can I have a day off tomorrow, Mr. Johnson?
— ________. I can manage without you.
A. Forget it. B. I’m afraid not. C. It depends. D. Of course.
12. ________ with care, one tin will last for six weeks.
A. Use B. Using C. Used D. To use
13. ________ at the door before you enter my room, please.
A. Knock B. Knocking C. Knocked D. To knock