positive: "题目<br>答案解析<br>查看更多优质解析<br>举报<br>1.并列结构中,or通常用于否定句,and用于肯定句.但有时and 也可用于否定句.请注意其不同特点:<br>There is no air or water in the moon.<br>There is no air and no water on the moon.<br>在否定中并列结构用or 连接,但含有两个否定词的句子实际被看作是肯定结构,因此要用and.<br>2.or用于连接并列的单词、词组、短语或句子,表示""或者""的意思.如:<br>We can visit the World Park or travel around the world.<br>我们可以参观世界公园,或者周游全世界.<br>3.or用在选择疑问句中,灵活译为""还是"".如:<br>Is that an apple or an orange?那是苹果还是桔子?<br>4.or用于否定句中,代替and ,表示""和""的意思.如:<br>I don't like bread ,rice or porridge.我不喜欢面包、米饭和粥.<br>5.or用于连接两个并列的句子,表示""否则,要不然""的意思.如:<br>Hurry up,or you'll be late.快点,否则你要迟到啦.<br>祝你学习愉快!<br>解析看不懂?求助智能家教解答<br>查看解答<br>相似问题<br>二维码<br>回顶部"
negative: AnalysisofFunctionalPerformanceofRemovableRotationFlatsofDifferentMaterialsofCardingMachineHEShanshan1 ,ZHANGYi2(1.CollegeofTextiles , DonghuaUniversity , Shanghai201620 , China ;2.ZhejiangChangshanTextileCo. , Ltd. , Quzhou324200 , China )Abstract : ThecausesofheelGandGtoesectionabrasionofremovablerotationflatsofcardingmachinewereexplainedbyanalyzingthestructureoftheremovablerotationflatsofcardingmachineanditsrunningstateduringoperationincardingarea , andameasurementmethodonheelGandGtoesectionwasproposed.ContrastexperimentswereconductedonfrequentlyGusedcastironrotationflatsandaluminiumalloyrotationflats.Theresultsshowedthataluminiumalloyrotationflatsperformedbetterinreducingenergyconsumptionofcardingmachineandextendingtheservicelifeofremovablecoverplateforitsadvantagesofgoodyarnquality , highwearresistance , andlightweight.Keywords : cardingmachine ; rotationflats ; heelGandGtoesection ; abrasion ; energyconsumption ;antiGabrasion