`27.D`

`=>`Dẫn chứng : It comes from household chemicals, the amount of water people use and the waste people produce and throw away. ( Câu 2 đoạn 1 )

`28.B`

`=>`Dẫn chứng : First, we need to recycle, which allows products to be used over and over again. ( Câu 1 đoạn 2 )

`29.C`

`=>`Dẫn chứng : Second, we need to watch the amount of water used at home. It can be conserved by taking short showers instead of baths, repairing leaky faucets, using the dishwasher or washing machine only when fully loaded, or simply turning the faucet off while brushing your teeth. (Đoạn văn số 3 )

`30.C`

`=>`Dẫn chứng : For example, grass clippings and food scraps can be made into compost for plants. The average person produces 4.3 pounds of waste every day, but we can reduce that amount by recycling and reusing. ( Câu cuối cùng của đoạn 4 )

`31.A`

`=>`Dẫn chứng : Recycling can also reduce the number of trees cut down to produce paper products. It takes very little effort.