Unit 3 Life in the future第I卷（选择题）I. 阅读理解AFor years scientists have been worried about the effects of air pollution on the earths natural conditions. Some believe the air inside many houses may be more dangerous than the air outside. It may be one hundred times worse.Indoor air pollution can cause a person to feel tired,to suffer eye pain, headache and other problems. Some pollutants(污染物质) can cause breathing disorders,diseases of blood and even cancer. Most scientists agree that every modern house has some kind of indoor pollution.People have paid more attention to the problem now. It is said that when builders began making houses and offices,they did not waste energy. To do this they built buildings that limited the flow of air between inside and outside. They also began using man-made building materials. These materials are now known to let out harmful gases.As the problem became more serious,scientists began searching for a way to deal with it. They discovered a natural pollution control system for building green plants. Scientists do not really know how plants control air pollution. They believe that a plants leaves absorb(吸收；吸引) or take in the pollutants. In exchange the plant lets out oxygen through its leaves and small organizations on its roots. Scientists suggest that all buildings should have one large plant or several small plants inside for every nine square meters of space. Studies of different plants show that each absorbs different chemicals. So the most effective(有效的) way to clean the air is to use different kinds of plants. Having green plants inside your house can make it prettier and more healthy place.1Generally speaking,indoor air pollution may be more harmful than that outside because _.A. indoor air pollution can often make people seriously illB. man-made building materials give off dangerous gasesC. there may be more harmful gases outside the buildingsD. the flow of air indoors is limited,which is very harmful2Some kind of indoor pollution can be found in _.A. every modern house B. every old houseC. all kinds of houses D. all kinds of offices3The indoor air pollution is caused by _.A. the limit of the flow of air between inside and outsideB. the building way that the builders want to save energyC. the building things that are made of man-made materialsD. the man-made building materials and the limit of air-flow4The reason why we should use different kinds of plants to clean the air is that _.A. plants can let out all kinds of pollutants indoorsB. plants may take in more oxygen which people needC. plants can absorb some kinds of harmful indoor chemicalsD. plants can make our houses prettier and more healthyBMetro Pocket GuideMetrorail(地铁)Each passenger needs a farecard to enter and go out. Up to two children under five may travel free with a paying customer.Farecard machine are in every station, Bring small bills because there are no change machines in the station and farecard machine only provide up to $ 5 in change.Get one of unlimited Metrorail rides with a One Day Pass. Buy it from a farecard machine in Metro stations. Use it after 9:30 a.m. until closing on weekdays, and all day on weekends and holidays.Hours of ServiceOpen: 5 a.m. Mon-Fri 7a.m. SatSun.Close midnight SunThur. 3. a.m. Fri Sat. nightsLast train times vary. To avoid missing the last train, please check the last train time posted in the station.MetrobusWhen paying with exact change, the fare is $ 1.35. When paying with a smatTrip CARD the fare is $1.25Fares for the Senior /disabled customersSenior citizens 65 and older and disabled customers may ride for half the regular fare. On Metrorail and Metrobus, use a senior/disabled farecard or SmarTrip card. For more information about buying senior/disabled farecards, farecard or smartrip card and passes, please visit MetroOpenDoors.com or call 202-637-7000 and 202-637-8000.Senior citizens and disabled customers can get free guide on how to use proper Metrobus and Metrorail services by calling 202-962-1100Travel tips. Avoid riding during weekday rush periods before 9:30 a.m. and between 4 and 6 p.m. If you lose something on a bus or train or in a station, please call Lost & Found at 202-962-1195.5What should you know about farecard machine?A. They start selling tickets at 9:30 a.m.B. They are connected to change machines.C. They offer special service to the elderly.D. They make change for no more than $5.6At what time does Metrorail stop service on Saturday?A. At midnight B. at 3 a.m. C. at 5 am D. at 7 p.m.7What is good about a smartrip card?A. It is convenient for old people B. It saves money for its usersC. it can be bought at any time D. it is sold on the Internet8Which number should you call if you lose something on the Metro?A. 202-962-1195 B. 202-962-1100 C. 202-673-7