16. These three Rs _________ reduce, reuse and recycle. A. stand up B. stand for C. ask for D. means 17. If there is a rubbish bin in every class, the classroom will become ______. A. harmful B. lighter C. dirtier D. cleaner 18. “Don’t throw rubbish into the river because you will make it _________” A. greener B. dirty C. cleaner D. fresher 19. If we use ________ paper, we will save a lot of trees. A. fewer B. less C. more D. much 20. I __________ you if you need my help. A. am helping B. could help C. will help D. helped 21. If someone into the store, smile and say, “May I help you?” A. comes B. came C. will come D. would come 22. If you ______all of my questions, I______ anything to help you. A. don’t answer / can’t do B. didn’t answer/ won’t do C. wouldn’t answer/ can’t do D. wouldn’t answer/ couldn’t do 23. “Here’s my phone number.” - “Thanks, I_____ you a call if I _____some help.” A. will give / will need B. would give/ needed C. give/need D. will give/ need 24. The teacher was absent today, so the class was canceled. If she_____ absent again tomorrow, class _____tomorrow, too. A. is / will cancel B. is/ will be canceled C. was / would be canceled D. was/ would cancel 25. I won’t lend you this money you promise to pay it back. A. in case B. if C. otherwise D. unless 26. _____there are some more ideas, we can end the meeting now. A. Unless B. If C. As if D. In case 27. “It’s really raining.”“Yes. If the weather______, we’ll have to camp somewhere else. A. would get worse B. might get worse C. gets worse D. should get worse 28. If anyone _______him I ______ back at 9 o’clock. A. calls / tell / will be B. called / telling / would be C. is calling / tells / am D. will call / to tell / am 29. If she asks for money, I her. A. will give B. gave C. would give D. would have given 30. If I _______this exam, I’ll go to the university next summer. A. pass B. to pass C. had passed D. passed