36/ What can we do______________air pollution? A/ Reduce B. To reduce C. Reducing D. To reducing 37/ If we________waste paper, we will save a lot of trees. A/ Repeat B. Recycle C. Rewrite D. Remark 38/ You can save money while shopping by only buying _________you need. A/ What B. This C. It D. That 39/ Why do you often forget to _ the lights when you go out of the classroom? A/ Turn on B. Turn off C. Close D. Shut down 40/ If we plant more trees in the schoolyard, the school will become a ________place. A/ Darker B. Greener C. Dirtier D. More polluted 41/ Do you think we should put a bin in every classroom in order to keep it clean? A. Reusable B. Recycled C. Recycling D. Recyclable 42/ My brother and I will give last year’s clothes to instead of throwing them away. A. Shop B. People C. Charity D. Survey 43/ Next week our class is having a discussion about finding ways to reuse old items before throwing them away. A/ Interested B. Surprising C. Useless D. Creative 44/ It is a good idea to our clothes with our friends or cousins. A/ Change B. Swap C. Turn D. Send 45/ If people turn off all electric appliances in one hour all over the world, they can save lots of . A/ Electric B. Electrical C. Electrician D. electricity 46/ You should put the food in a reusable box plastic bags. A/ By B. Instead of C. Because of D. Without 47/ If we use paper, we will save a lot of trees. A/ Fewer B. Less C. More D. Much 48/ Don’t throw rubbish into the river because you will make it . A/ Greener B. Dirty C. Cleaner D. Fresher 49/ If there is a rubbish bin in every class, the classroom will become ________. A/ Harmful B. Lighter C. Dirtier D. Cleaner