第一盒中有4个红球6个白球,第二盒中有5个红球5个白球,随机地取一盒,从中随机地取一个球,求取到红球的概率。
随机地取一盒,则每一盒取到的概率都是0.5,所求概率为:p=0.5×0.4+0.5×0.5=0.45
暂无解析
John'sscoreonthetestisthehighestintheclass;he____lastnight.
The____populatedareawasabreedingplaceforinfectiousdiseases.
Humanbeingsaresuperiortoanimals_____theycanuselanguageasatooltocommunicate.
Writing:
InChina,torestorelostpropertytoitsoriginalownerisregardedasoneofthemostcherishedvirtues.However,thedraftpropertyrightslawstipulatesthatpropertyOwnersshouldpaysomemoneytotheonewhoreturnstheproperty.Isitadeviationfromtraditionalvalues?Writeacompositionofabout400wordstostateyourview.
Inthefirstpartofyouressayyoushouldstateclearlyyourmainargument,andinthesecondpartyoushouldsupportyourargumentwithappropriatedetails.Inthelastpartyoushouldbringwhatyouhavewrittentoanaturalconclusionormakeasummary.
Youshouldsupplyanappropriatetitleforyouressay.
Markswillbeawardedforcontent,organization,grammarandappropriateness.Failuretofollowtheaboveinstructionsmayresultinalossofmarks.