2021英语四级听力：Population Growth思维导图

Itiswell-knownthattherehasbeenadrasticincreaseinworldpopulation.Butitisprobablyleswell-knownthattheextinctionrateofwildlifespeciesisexperiencingaparalleltrend.

TaketheUnitedStatesforinstance.In1990,U.S.populationreachedanunprecedentedlevelof250million,whichisapproximately250timesofthatof1800.Ontheotherhand,wildlifespeciesaredisappearingfromthecountryatanalamp3ingrate.By1990,about70wildlifespecieswouldneverbeseeninU.S.Wearefullyjustifiedindeclaringthattheexplosivepopulationgrowthhashadanadverseeffectonthesurvivalofwildlifespeciesandwillbeaconstantthreattothewildliferesourcesifnoimmediateactionsaretaken.

Nothinghaseverequaledthemagnitudeandspeedwithwhichthehumanspeciesisalteringthephysicalandchemicalworld.Ithasbeendemolishingtheenvironmentwearelivingin.

Usefulwordsandexpressions:

1.drastic激烈的

2.parallel平行的

3.trend倾向

4.unprecedented空前的

5.magnitude大小，数量

6.alter改变

7.demolish毁坏