Theworldisnotonlyhungry,itwillalsobethirstyforwater.About97%ofwaterontheearthisseawater,orsalty(咸的)water.Mancanonlydrinkorusetheother3%ofthefreshwater(淡水)whichcomesfromrivers,lakesandunderground.T

　　Theworldisnotonlyhungry,itwillalsobethirstyforwater.About97%ofwaterontheearthisseawater,orsalty(咸的)water.Mancanonlydrinkorusetheother3%ofthefreshwater(淡水)whichcomesfromrivers,lakesandunderground.

　　Theseaisverybig.Lookatthemapoftheworld,thereismoreseathanland.Itcovers(覆盖)quartersoftheearth,itlooksverybeautifulwhenthesunisshinningonit.butitcanbeterriblewhenthereisastrongwind.

　　Somepartsoftheseaareverydeep.ThereisoneplacenearJapan.It'snearly11kilometershigh.Ifweputthatmountainintotheseaatthatplace,therewouldbe2kilometersofwateraboveit!

　　Theseaissalty.Thereisone"sea"calledtheDeadSea.TheDeadSeaisnotasea.It'sabiglakeintheJordanValley.It'sthesaltiest.It'snearthecityofJericho.It'sabout80.kilometreslong,between4.8and17.7kilometerswide.TheriverJordanrunsintotheDeadSea.Thesunisnotthereandthewaterissalty.Fishcan'tliveintheDeadSeaandplantscan'tgrownearit.Peoplecan'tswimwellintheDeadSea,buttheycan'tfloat(漂浮)onthewater.Thewaterisveryblueandtheairisclean.InwinterpeoplecometotheDeadSeatoenjoythesunshine.

　　46.Doesthefreshwatercomefromrivers,lakesandunderground?

　　A.Yes,itdoes.B.No,itdoesn't.C.Yes,itdoesn't.D.No,itdoes.

　　47.Thedeepestplaceintheseaisnear.

　　A.JapanB.IndiaC.AmericaD.China

　　48.Thepassagetellsustheseacoversoftheearth.

　　A.3%B.25%C.75%D.97%

　　49.TheDeadSeais.

　　A.80kilometerslongB.2kilometerswide

　　C.11kilometersdeepD.17.7kilometershigh

　　50.Accordingtothepassage,whichofthefollowingisn'ttrue?

　　A.TheriverJordanrunintotheDeadSea.

　　B.Theworldwillbethirstyforwater.

　　C.Thesealooksbeautifulwhenthesun-isshiningonit.

　　D.TheDeadSeaisthesaltiestseaintheworld.