18. If we go on littering, the environment _________seriously polluted. A. becomes B. will become C. became D. would become 19. The boy was very hungry _________he ate nothing. A. so B. and C. therefore D. but 20. The man suggests _________to the seaside in the summer. A. to go B. go C. going D. goes 21. A dripping faucet_________500 liters of water a month. A. can waste B. is wasted C. waste D. are wasting 22. He sighed _________when he heard the news. A. sadly B. sad C. sadden D. sadness 13. Please _________the lights. It’s very dark. A. turn on B. go on C. get on D. put on 24. Not only _________her father, but you will know about his job if you go with us. A. you meet B. will you meet C. you are meeting D. do you meet 25. The man sat down on the chair _________started to tell the story. A. so B. and C. or D. because 26. You should travel by bike _________by motorbike to save energy. A. therefore B. instead of C. however D. because 27. Please go _________with what you’re doing. Don’t look at them! A. on B. out C. away D. down 28. The new appliance does not only work _________ but also saves energy. A. effect B. effective C. effectively D. effectiveness

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