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sure D Not very well. 8. We ____________always be careful with electricity. It is dangerous. A must B mustn39。t 9. You _________ be absentminded in class. A mustn39。t C may not D needn39。t smoke. B You don39。d better smoke. 12. To protect the environment, some scientists want to _______ deserts ________ forests. A change。 to C take。 to 13. What can I do for you? I39。t ___________my questions. A answers B answer to C reply D reply to 15. I washed a lot of clothes. Who can __________? A tidy up them B tidy them up C tidy it up D tidy up it