简介：Stamp-collectingisaveryinterestingusefulhobby(嗜好),YOucanlearnmanythingsaboutgeographyandhistoryfromstamps.TodaymorepeoplecollectStampsthaneverbefore,andspecial(特殊的)stampsareoftenprintedforthepeople.Ifyoubuyanewstampandputitonanenvelope(信封)onthefirstdaywhenitissold,theenvelopemaybeworthalotofmoneyinthefuture.

简介：Lasttimeweintroducedsomelaboratoryapparatuscommonlyusedtomeasuremass，temperatureandthevolumeofliquids．Onethingneedstobementionedhere．Whenwaterorsomesolutionisplacedinaglassvessel，it

简介：同学们，现在让我们一起来学习第六单元吧!在本单元，大家将通过谈论做某事多长时间了，以及自己与别人的兴趣爱好来学习现在完成进行时，并且通过教材的各个环节的学习来体会现在完成进行时与一般过去时的区别。并为以后正式学习现在完成时打好基础。本单元的语法内容是现在完成进行时，对于同学们来讲，可能有些难哦，现在请同学们跟我一起来学习。

简介：Themethodforcollectingeggsofthestripedstemborer.Chilosuppressalisusingplasticbagswasstudiedincomparisonwithusingcagedriceplants.TherewasnosignificantdifferenceinfecundityofC.suppressalisat279eggs/mothandinpercentageofhatchedeggsat95%betweeninplasticbagsandonriceplants.Moreeggmasseswerecollectedonplasticbagsthanonriceplants,whereasmoresmallereggmasses(lessthan100eggspermass)inplasticbagsthanonriceplants.TheadvantagesincollectingeggsofC.suppressalisandotherinsectsbyusingplasticbagswerealsodiscussed.

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