positive: 1. 表示选择,意为“或”“还是”:<br>Is the radio off or on? 无线电关上了还是开着的?<br>Would you prefer tea or coffee? 你喜欢茶还是咖啡?<br>Is he asleep or awake? 他睡着了还是醒着?<br>Are you going to America by boat or by air? 你到美国是坐船还是坐飞机?<br>You may go or stay, according as you decide. 是去是留由你自己决定。<br>Are you from North China or South China? 你是华北人还是华南人?<br>You can come now or you can meet us there later. 你可以现在来,也可以稍晚和我们在那里碰头。<br>2. 表示一种否定的条件,意为“否则”:<br>Come on, or we’ll be late. 快点,否则我们要迟到了。<br>Hurry up, or you'll be late for school. (from www.yingyuyufa.com)赶快,否则你上学就要迟到了。<br>Dress warmly, or else you’ll catch cold. 穿暖和点,否则你会感冒的。<br>Be careful, or you’ll break that vase! 小心,否则你会把那花瓶打碎!<br>Cross the road very carefully. Look both ways, or you might be knocked down. 过马路要非常小心,要看两边,不然会被车撞倒。<br>3. 可表示“要不就是”:<br>He must be joking, or else he’s mad. 他一定在说笑话,要不就是疯了。<br>The book must be here, or else you’ve lost it. 这书一定在这儿,要不就是你丢失了。<br>4. 用于否定句中代替and。<br>He was not clever or good-looking. 他不聪明,也长得不好看。<br>比较:<br>They sang and danced
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