托福听力考试背景学问综合辅导(五)

托福听力考试背景学问综合辅导(五)Rainforest LayersHigh temperature and rainfall production, more or less uniform th

() 托福听力考试背景学问综合辅导五 RainforestLayersHightemperatureandrainfallproduction, moreorlessuniformthroughouttheyear,characterizethe rainforestworldwide.Thewaterthatisrequiredto maintainthisenvironmentalsothreatensitsexistence.If leftuncontrolled,thewaterthatconstantlybombardsthe soilwouldleechoutmostofthevaluablenutrients.Plants andanimalsinthisenvironmenthavedevelopedadaptations todealwiththeconstantdelugeandtocompete successfullyfornutrients. Acloserlookattherainforestrevealsthatitisactually composedoffourlayersorcommunities.Eachlayerhasa uniquesetofenvironmentalconditionsandorganisms adaptedtothem.Readthedescriptionsbelowandwatchfor theselayersandtheinfinitevarietyoflifeformsthat occupythemasyouvisitLaSelva.TheEmergentLayer Thetallesttreesaretheemergents,toweringasmuchas 200feet(60m)abovetheforestfloorwithtrunksthat 15 第页共页