6[单选题] 人造地球卫星，绕地球作椭圆轨道运动，地球在椭圆的一个焦点上，则卫星的 A.动量不守恒，动能守恒． B.动量守恒，动能不守恒． - 查题网

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河南成教 / 大学物理

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6[单选题]
人造地球卫星，绕地球作椭圆轨道运动，地球在椭圆的一个焦点上，则卫星的

A.动量不守恒，动能守恒．

B.动量守恒，动能不守恒．

C.角动量守恒，动能不守恒．

D.角动量不守恒，动能守恒．

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大学物理

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2[填空题] 　 Ancient Greek philosopher Aristotle viewed laughter as “a bodily exercise precious to health.” But __1___some claims to the contrary, laughing probably has little influence on physical fitness Laughter does __2___short-term changes in the function of the heart and its blood vessels, ___3_ heart rate and oxygen consumption But because hard laughter is difficult to __4__, a good laugh is unlikely to have __5___ benefits the way, say, walking or jogging does. __6__, instead of straining muscles to build them, as exercise does, laughter apparently accomplishes the __7__, studies dating back to the 1930’s indicate that laughter__8___ muscles, decreasing muscle tone for up to 45 minutes after the laugh dies down. Such bodily reaction might conceivably help _9__the effects of psychological stress. Anyway, the act of laughing probably does produce other types of ___10___ feedback, that improve an individual’s emotional state. __11____one classical theory of emotion, our feelings are partially rooted ____12___ physical reactions. It was argued at the end of the 19th century that humans do not cry ___13___they are sad but they become sad when the tears begin to flow. Although sadness also ____14___ tears, evidence suggests that emotions can flow __15___ muscular responses. In an experiment published in 1988,social psychologist Fritz Strack of the University of würzburg in Germany asked volunteers to pick a pen either with their teeth-thereby creating an artificial smile – or with their lips, which would produce a(n) disappointed expression. Those forced to exercise their smiling muscles reacted more exuberantly to funny cartons than did those whose mouths were contracted in a frown, mentioning that expressions may influence emotions rather than just the other way around Similarly , the physical act of laughter could improve mood. 1．[A]among [B]except [C]despite [D]like 2．[A]reflect [B]demand [C]indicate [D]produce 3．[A]stabilizing [B]boosting [C]impairing [D]determining 4．[A]transmit [B]sustain [C]evaluate [D]observe 5．[A]measurable [B]manageable [C]affordable [D]renewable 6．[A]In turn [B]In fact [C]In addition [D]In brief 7．[A]opposite [B]impossible [C]average [D]expected 8．[A]hardens [B]weakens [C]tightens [D]relaxes 9．[A]aggravate [B]generate [C]moderate [D]enhance 10．[A]physical [B]mental [C]subconscious [D]internal 11．[A]Except for [B]According to [C]Due to [D]As for 12．[A]with [B]on [C]in [D]at 13．[A]unless [B]until [C]if [D]because 14．[A]exhausts [B]follows [C]precedes [D]suppresses 15．[A]into [B]from [C]towards [D]beyond综合英语(二)

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