你可以稍微缩减一点 　　Tropicalrainforestsgrowinwarm,wetareas----CentralAmericaSouthAmereica,Arica,andSoutheastAsia.Becauseitrainsalotthere.Withsomuchrain,thesoilinrainforestsisverydarkandrichforplantstogrow.Morethanhalfofthetropicalplantsintheworldgrowinrainforest.Thousandsofanimalsliveinthem,too. 　　Rainforestsmakeuplessthan8%oftheearth,butmorethan50%oftheplantsandanimalsontheearthliveinthem.Thickplantsmakeitdifficulttogoveryfarintotheforest.Mostexploringmustbedoneonfoot,orbyboat.Therefore,therearelargeareasthathaven'tbeendiscovered 　　yet. 　　Tropicalrainforestsarerichforfood,medicineandotherusefulthings. 　　Today,sadly,rainforestsarethreatened(威胁)bysuchthingsasacidrainfromfactorysmokeemissions(散发)aroundtheworldandfromfarmexpansion(扩张).Alotofrainforestsareburnedorcutdowneachyear.Thelandisusedforfarmingofforbuildingfactories.Becauseofthelossofrainforests,1000kindsofplantsandanimalsbecomeextinct(灭绝). 　　Manypeopleunderstandtheimportanceofsavingtherainforests.Manycountriesaremakingrainforestsintonationalparks.Farmersarebeingtaughthowtogrowcropswithouthurtingtherainforests. 　　Perhapsyoucandosomethingtohelpprotecttherainforestsoftheearth.