OnSunday,April22,1990,peopleallovertheworldcelebratethesameholiday.Itwasthetwentiethanniversary(周年)ofEarthDay.Thepurposeoftheholiday,whichwecelebrateeveryyearonthatdate,istohelppeoplelearnhowtoprote

　　OnSunday,April22,1990,peopleallovertheworldcelebratethesameholiday.Itwasthetwentiethanniversary(周年)ofEarthDay.Thepurposeoftheholiday,whichwecelebrateeveryyearonthatdate,istohelppeoplelearnhowtoprotecttheplanetEarth.PeoplearoundtheworldcelebrateEarthDaybecausetheyworryabouttheplanet.Manyformsofanimallifearedisappearingfromtheearth.Carelessnessandaccidentsinmanycountrieshavecausedharmfulproblemstotheenvironment.Airandwaterpollution,oilspills(溢出),andpoisonous(有毒的)wastearesomeoftheseriousproblems.

　　Infact,protectingtheearthistrulyaworldwideproblem.Anaccidentinanuclearpower(核电)plantinonecountrycancreatearadioactive(有辐射的)cloudthatgoeshalfwayaroundtheworld.Factorysmokeinonecountrycancreateacidrain(酸雨)oilthatfloats(漂)totheshoresofanother.Itiseasytoseehowourprotectingtheenvironmenthasbecomeaninternationalissue.

　　So,inordertobeginthedifficultjobdrivesofsavingtheearth,peoplearoundtheworlddidspecialthingsonEarthDay,1990.InJapan,driverspulledgarbagefromthesea.InNepal(尼泊尔),climberspickeduptrashonMountEverest(珠穆朗玛峰).StudentsmarchedinsupportofEarthDayinHongKong,andpeoplegrewmedicinalplantsinthePhilippines.IntheUnitedStates,childrenplantedtrees.NativeAmericanstoldstoriesaboutthecreationoftheearth,artistsdrewonwallsnexttohighways,andmusiciansgaveconcertstosupporttheworkofenvironmentalgroup.Almosteveryoneeverywherestoppedforamomenttothinkabouthowwecanprotecttheearth.

　　Choosethebestanswer:

　　WebegantocelebrateEarthDayin________.

　　A

　　1990

　　B

　　1971

　　C

　　1979

　　D

　　1965

　　Accordingtothepassage,thepresentenvironmental(环境)problemismainlycausedby________.

　　A

　　thedevelopmentofscienceandtechnology

　　B

　　theradioactivewastesfromnuclearpowerplants

　　C

　　theleakingofoilinoiltankers

　　D

　　people'scarelessnessandaccidents

　　Theunderlinedword“trash”(para.3)means________.

　　A

　　垃圾

　　B

　　盘子

　　C