All over the world，forests are safeguarding the health of the planet itself. They do this 1 protecting the soil, providing water and 2 the climate. Trees 3 soil to mountainsides. Hills 4 the trees have been felled lose 500 times as 5 soil a year as those with trees.

　　Trees catdb and 6 rainwater. Their leaves break the impact 7 the rains, roKhing them of 8

　　destructive poiger. The roots of trees allow the water t0 go into the soil, 9 gradually releases it to flow down

　　rivers and Tefill gp&tttid-water reserves. 10 there are no trees, the raiiw run in sheets of smter off the land,

　　11 the soil with them. Land 12 with trees and other plants 13 20 times more rainwater than 14

　　earth. As they grow, trees absorb carbon dioxide, the main 15 of the ‘‘greenhouse effect”，which 16

　　irreversibly to change the world’ s climate. Together，the world’ s trees，plants and soils contain three times 17

　　much carbon as there is in the atmosphere.

　　The world ’ s forests contain the vast majority of 18 animal and plant species. The tropical rainforests

　　19have well overhalf of them，20 theycover only about 6% of the Earth*s land surface.

　　1.A.forB.formC.byD.with

　　2.A.adoptingB.regulatingC.transformingD.controlling

　　3.A.bindB.requirec.giveD.offer

　　4.A.thatB.whichc.whereD.there

　　5.A.lessB.morec.manyD.much

　　6.A.storeB.transmitc.attractD.catch

　　7.A.onB.withc.ofD.for

　　8.A.itsB.thesec.thoseD.their

　　9.A.thatB.itc.whatD.which

　　10AWhenB.Wherec.WhileD.Although

　　11. A.bringingB.carryingC. takingD.missing

　　12. A.coveredB.occupiedC. settledD.fixed

　　13. A.absorbsB.reducesC. engagesD.provides

　　14. A.plainB.emptyC. bareD.simple

　　15. A.reasonB.effectC. purposeD.cause

　　16. A.warnsB.attemptsC. threatensD.approaches

　　17. A.asB.moreC. thatD.so

　　18. A.itsB.theirC. theseD.those

　　19. A.onlyB.lonelyC. aloneD.itself

　　20. A.no matterB.in spiteC. in thatD.even though

　　参考答案

　　参考答案

　　1-5、CBACD　　6-10、ACDDB　　11-15、BAACD　　16-20、CAACD