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【单选题】
Todayalmost70%oftheelectricalpowerweuesfrompowerplantsthatusefossilfuels(矿物燃料)tomakeelectricity.Fossilfuels,suchasoil,coal,andnaturalgas,areburnedtomakeelectricity.Burningfossilfuelsreleasespollutionandcarbondioxidegas(C02)intotheair.Themorefossilfuelsweburn,thewarmertheairaroundEarthgets.Sobuildingfossilfuelplantsisnotalwaysthebestanswer.Actually,thereareotherwaystomakeelectricitywithoutburningfossilfuels.Peoplehavebeenusingthepowerofwindforcenturies.Windpowerwon'tsolveallourenergyproblems,butitcanhelpmeetsomeofthedemandsincertainplaces.Sincethelate1800s,scientistshavebeenworkingtoturnthesun'senergyintoelectricitybyusingsolarcells(太阳能电池).Theproblemis,solarcellsareveryexpensive.Anotherwaytomakeelectricityistousenuclearenergy.Ithasbeenusedformorethan50years.Todayabout10percentofalltheelectricityusedintheU.S.
A.
comesfromthissource.Althoughnuclearpowerdoesn'tpollutetheairastheburningoffossilfuelsdoes,thereisamajordrawback.Thewasteproductsfromnuclearpowerplantsareerousandmustbestoredinsafeplaces.Manypeopleareconcernedaboutthesafetyofnuclearpower.Thebesttitleforthispassagemaybe______.A．TheImportanceofElectricityB．ThePollutionofElectricityfromFossilFuelsC．TheAdvantageofUsingNuclearEnergyD．MeansofElectricalPower
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【单选题】有三个电池 设这三个电池中各物质浓度都是0.1molL-1，则它们的（）
A.
电池反应式不同，ε不同
B.
电池反应式不同，ε相同
C.
电池反应式相同，ε相同
D.
电池反应式相同，ε不同
【多选题】关于日常使用的干电池说法正确的有
A.
使用时需要识别区分正、负极
B.
要根据电压选择使用电池
C.
不同型号的干电池，提供电能是相同的
D.
要根据使用场合，选择适合电池外形尺寸
【单选题】All over Europe, and in North America, there’re lakes and forests which are dead or (71) and the (72) is thought to be acid rain. What is acid rain Mr. Justin Cook, a scientist, explains: "All fossil ...
A.
All over Europe, and in North America, there’re lakes and forests which are dead or (71) and the (72) is thought to be acid rain. What is acid rain Mr. Justin Cook, a scientist, explains: "All fossil fuels, (矿物燃料)，that (73) oil, coal and gas, contain sulphur. When these are burnt, for example (74) motor vehicles, they form sulphuric acid (硫酸)This (75) UP into the air, and soon it falls back to (76) , into lakes and (77) trees in forests." This can cause many local problems. 78 a result, lakes become acidic, fish disappear and trees are killed. The pollution is carried great distances by the wind, so sulphuric acid (79) in Britain can travel as far as Scandinavia (斯堪的纳维亚). Czech is one of the countries with the most acid rains and large areas of (80) consist only (81) dead trees.
B.
Is there (82) that can be done about acid rain Mr. cook says: "The rain (83) of acid rain is (84) power stations to install filters that (85) the acid getting out into the air. Here in Britain, the only (86) that has been taken is that the chimneys are built (87) so that the pollution is more distributed." If the petrol used in motor vehicles (88) lead--free, then it Would be possible to filter exhaust fuses (废气) which are a (89) cause of pollution. But these filter mechanisms (机械装置)can not work (90) the leads is removed.