Unit 2 Topic 2 Section B（限时训练） 一、单项选择( )1.Watching TV too much _ bad for your eyes.Ill go to bed right away.A. isB. areC. wasD. be( )2.If you feel _, you should go to school.A. badB. worseC. betterD. good( )3.How often do you exercise?_A. Less than three times a week. B. More than 10 hours.C. From one thirty to three.D.I often do it.( )4._ necessary for us _ English well.A. This is; to learn B. Its; to learnC. Its; learnD. Thats; learn( )5.If you eat _ food and take _ exercise, youll keep healthy.A. more; more B. less; lessC. more; less D. less; more( )6.Humans cant live _ air.I agree with you.A. withoutB. withC. inD. for( )7.I cant keep myself active during the day.You _ take more exercise.A .must notB. must beC. need toD. may be( )8.This article says _ is bad for our lungs.A. smokeB. to smokeC. smokedD. smoking( )9.You had better ask your brother _ playing computer games. Its bad for him.A. to give upB. not to give upC. to give it upD. not give it up( )10.You _ walk across the road. Its dangerous.A. may notB. dont have to C. must notD. neednt( )11.Tom must _ at home. A. is B. be C. D. go 二、根据语义完成句子。1.脏水使他肚子疼。The dirty water _ his stomachache _.2.我一定让他戒烟（放弃吸烟）。I must ask him to _ _ _.3.别乱丢垃圾。Dont _ _ _4.对我们来说，每天刷两次牙很有必要。Its _ for us to brush teeth twice a day.注意运用句型：Its necessary for sb. to do sth.5.他不够上学的年龄。He is not old _ to go to school.6.我们来得及赶到机场。We have _ time/time _ to get to the airport. 注意辨别以上两句中enough的位置。答案一1-5. ACABD 6-10. ACDAC 11. B二1. makes；pain 2. give up smoking 3. throw about litter4. necessary 5. enough 6. enough/enough2