0  389391  389399  389405  389409  389415  389417  389421  389427  389429  389435  389441  389445  389447  389451  389457  389459  389465  389469  389471  389475  389477  389481  389483  389485  389486  389487  389489  389490  389491  389493  389495  389499  389501  389505  389507  389511  389517  389519  389525  389529  389531  389535  389541  389547  389549  389555  389559  389561  389567  389571  389577  389585  447090 

29. During the flight to the Moon, Chang’e I Satellite__adjusts her direction so that she can go into her programmed orbit and then circle around it at the most appropritate angle(角度).  (08 全国I)

  A. and           B. whereas          C. thus           D. so

试题详情

28. The __ om his face told me that he was angry.  (06 湖北)

  A.impression        B. Sight            C. appearance      D.expression

试题详情

27. The open-air celebration has been put off __ the bad weather. (07 浙江)

  A. in case of        B. In spite of         C. Instead of       D. Because of

试题详情

26. The army office __ his men to fire as soon as the enemy came up.

  A. requested      B. commanded         C. begged         D.suggested

试题详情

25. ----What do you think __ an important part in their lives?

  ----Folk music.

  A. plays          B.takes            C. makes        D. acts

试题详情

24. He had changed so much that I didn’t __ him at first sight.

  A. know         B. realize           C. recognize       D. see

试题详情

23. As is known to all language learners, the newly learnt words will soom be forgotten unless__used in everyday communication.

  A. gradually        B. Accurately         C. familiarly     D. frequently

试题详情

22. When I give up work I shall take a long __ over sea.

  A. trip          B. Travel           C. journey         D. voyage

试题详情

第一节  多项选择(共10小题;每小题1分,满分10分)

   从A、B、C、D四个选项中,选出可以填人空白处的最佳选项。

21. He__ and asked me if I knew the time..

  A. came up with      B. Came about        C. Came up       D. Came across

试题详情

5.善于用淘汰法解答物理选择题

有一部分选择题,常涉及到对某个概念或规律的各个侧面的掌握情况或对某类综合问题的各个环节的考察,对此类问题,除了用相关知识从正面分析、推理外,还可采取从反面寻找反例,逐步淘汰的排除法得出正确结论。

例9、(2002年全国理科综合高考试题).在光滑水平地面上有两个相同的弹性小球AB,质量都为m。现B球静止,A球向B球运动,发生正碰。已知碰撞过程中总机械能守恒,两球压缩最紧时的弹性势能为EP,则碰前A球的速度等于   (   )

A.    B.    C.    D.

分析与解: 根据能量守恒可知,碰前A球的动能一定要大于EP,而若碰前A球的速度等于,则碰前A球的动能小于EP或等于EP,立即判定A、B二选项是错误的。若碰前A球的速度等于 ,则碰前A球的动能等于4EP,碰后两球的总动能应为3EP,碰前系统的总动量为,碰后系统的总动量为,不符合动量守恒,所以是错误的。本题正确答案为C选项。

例10、(2001年全国高考试题)细长轻绳下端拴一小球构成单摆,在悬点正下方摆长处有一个能挡住摆线的钉子A,如图13所示。现将单摆向左方拉开一个小角度,然后无初速地释放。对于以后的运动,下列说法中正确的是(  )

A.摆球往返运动一次的周期比无钉子时的单摆周期小;

B. 摆球在左、右两侧上升的最大高度一样;

C. 摆球在平衡位置左右两侧走过的最大弧长相等;

D.摆线在平衡位置右侧的最大摆角是左侧的两倍。

分析与解:本题的A、B选项是显然正确的。C、D选项是本题的难点,若改换思维角度逆向思考,以D选项为突破口,则可迅速作出判断。若D正确,则图13中所示各角度关系成立并得出OC<OB,即得出C位置应高于B位置的错误结论,故D错。判断出选项D错,则选项C便显然是错误的了。

试题详情


同步练习册答案