1、Unit 3 Couldyoupleasecleanyourroom?Section B 3a--3bTeachingAimsA.Enablestudentstowriteane-mailmessageaskingforhelp.B.Helpstudentslearnhowtowriteane-mailmessagewiththetargetlanguage.C.Enablestudentstodevelopagoodhabit.KeypointsExpressopinionsaboutdoinghouseworkDifficultpoin