Unit 7 Protect the Earth 习题2.doc

Unit 7 Protect the Earth 习题2 一、 单项选择。 1. --- What _____ we do to save energy?  --- We should not drive so much.      A. keep      B. should     C. makes    D. cans    2. --- How should we save plastic bags and bottles?    --- We should more paper bags and glass bottles. A. use  B. uses   C. can   D. keeps  3. We wood make tables chairs and many other things.  A. use; and    B. uses; to    C. use; to   D. uses; for 4. We cut too many trees because trees help us keep the air clean.  A. should    B. should not    C. can    D. keep 5. There is not much coal or oil on , so we save energy. A. earth; should   B. Earth; should not     C. Earth; should       D. earth; should not