问题 选择题

有关万有引力的说法中,正确的有

A.物体落到地面上,说明地球对物体有引力,物体对地球没有引力

B.中的G是比例常数,适用于任何两个物体之间,它没有单位

C.万有引力定律是开普勒在总结前人研究的基础上发现的

D.地面上自由下落的苹果和天空中运行的月亮,受到的都是地球引力

答案

答案:D

题目分析:地球对物体的引力和物体对地球引力是作用力和反作用力,同时存在.

G是引力常量,对于不同的星球G的值相同.

万有引力是普遍存在于宇宙空间中所有具有质量的物体之间的相互作用.

A、地球对物体有引和物体对地球引力是作用力和反作用力,同时存在.故A错误.

B、,中的G是引力常量,对于不同的星球G的值相同.故B错误.

C、万有引力是普遍存在于宇宙空间中所有具有质量的物体之间的相互作用,公式不仅适用于天体,还适用于地面物体,故C错误.

D、万有引力是普遍存在于宇宙空间中所有具有质量的物体之间的相互作用,地面上自由下落的苹果和天空中的行星都受到地球的引力,故D正确.

故选D.

点评:解决该题关键要掌握万有引力定律得内容和适用条件.

完形填空

One spring afternoon five years ago, Jimmy Liao was crying in the hall of Taipei’s Sherwood Hotel, Life seemed  36  . The people who laughed as they walked past were taking their   37 

for granted, just as he  38  himself. Now, however, he felt  39  —and he couldn’t even show his disappointment in his  40  .

Seeking more personally satisfying  41  , he had just left a successful job as a commercial artist when it seemed that fate(命运)played a cruel  42  on him. It was at this time that he developed cancer and was  43  to work. But that moment in the hotel was a turning point for Jimmy. He began to  44  the fact that there is no such a thing as fate, only  45  . Since then, he has published several imaginative, illustrated(带插图的)books.

According to Jimmy, you are  46  you choose to be. You can give up or you can work to be a happier person. Jimmy realized that, while the world  47  seems unfair, your choice can change your life.

This idea can be   48  in Jimmy’s books, where his characters show the powerlessness they feel   49  making their choices. The message that goes with Jimmy’s drawings, however, is 50 .

Though the world may make us feel small, we must be  51  . Everything will be all right for us—as it is for the“small people”in Jimmy’s books—if we make choices that are   52  for us.

In spite of his new  53  and wealth, Jimmy prefers working  54  at home with his wife and daughter. He spends his mornings drawing. To Jimmy, living a life as he chooses means much more than money and fame could  55  .

36.A.unhappy                 B.unusual                   C.unfair                     D.uneasy

37.A.health                     B.wealth                    C.happiness                D.illnesses

38.A.ought to                 B.had to                     C.needed to                D.used to

39.A.ashamed                 B.disappointed            C.helpless                  D.endless

40.A.crying                    B.painting                  C.imagination             D.consideration

41.A.home                            B.condition                C.situation                 D.work

42.A.game                      B.trick                       C.role                        D.part

43.A.unable                    B.impossible              C.unfit                       D.difficult

44.A.understand              B.face                        C.refuse                     D.recognize

45.A.failures                   B.efforts                    C.choices                   D.interests

46.A.that                        B.what                       C.which                     D.whoever

47.A.always                    B.seldom                   C.sometimes               D.usually

48.A.found                     B.drawn                     C.written                   D.accepted

49.A.after                       B.about                      C.with                       D.before

50.A.powerful                B.hopeful                   C.useful                     D.successful

51.A.great                      B.strong                     C.brave                      D.equal

52.A.scientific                B.basic                      C.right                       D.simple

53.A.product                  B.fame                      C.name                      D.job

54.A.rapidly                   B.separately               C.slowly                    D.quietly

55.A.offer                      B.gain                       C.gather                     D.earn

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