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7.  ____ learning English through images or through association of ideas, there is also what is popularly known as “situation English”.

  A. In addition to             B. Except                  C. Except for       D. In addition

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6.  We shouldn’t complain about being poor-many families are much ____ than we are.

  A. better off                B. well off                 C. worse off        D. badly off

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5.  The poor man stood there, with his hands ____, ____ his eyes upon the dark cave.

  A. crossed, fixing            B. crossing, fixing

  C. crossed, fixed            D. crossing, fixed

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4.  Mary ____ he write a letter explaining why he didn’t turn up at her birthday party.

  A. supposed              B. hoped           C. expected        D. urged

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3.  People in Sichuan province are determined to rebuild ____ was destroyed in the earthquake.

  A. that                     B. which                  C. how             D. what

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2.  In the disaster area, plenty of people are short of ____ necessities ____ food, water and medicine.

   A. expensive, such as     B. basic, like  C. ordinary, that is    D. peaceful, for example

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第一节:单项填空(共20小题;每小题0.5分,满分10分)

1.    Mr. and Mrs. White are determined to give their children ____ first-rate education, though they are both out of ____ work now.

A. a, the                   B. the, the                C. a, /         D. the, /

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21.如图所示是建筑工地常用的一种“深穴打夯机”。工作时,电动机带动两个紧压夯杆的滚轮匀速转动将夯杆从深为h的坑中提上来,当两个滚轮彼此分开时,夯杆被释放,最后夯在自身重力作用下,落回深坑,夯实坑底。然后两个滚轮再次压紧,夯杆再次被提上来,如此周而复始工作。已知两个滚轮边缘线速度v恒为4m/s,每个滚轮对夯杆的正压力FN=2×104N,滚轮与夯杆间的动摩擦因数μ=0.3,夯杆质量m=1×103kg,坑深h=6.4m。假定在打夯的过程中坑的深度变化及夯与坑底的作用时间均忽略不计,且夯杆底端升到坑口时,速度恰好为零。取g=10m/s2,求:

(1)夯杆上升过程中被滚轮释放时的速度为多大?此时夯杆底端离坑底多高?

(2)每个打夯周期中,电动机对夯杆所做的功?

(3)打夯周期是多少?

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20.在与x轴平行的匀强电场中,一带电量为1.0×10-4C,质量为2.5×10-3kg的物体在光滑水平面上沿着x轴方向做直线运动,其位移与时间的关系是x=0.16t-0.02t2,式中x以m为单位,t以s为单位。从开始运动到5s末物体所经过的路程为多少?克服电场力做的功是多少?

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19.如图所示,皮带传动装置与水平面夹角为30o,轮半径R=m,两轮轴心相距L=3.75m,AB分别是传送带与两轮的切点,轮缘与传送带之间不打滑,一个质量为0.1kg的小物块与传送带间的动摩擦因数。小物块相对于传送带运动时,会在传送带上留下痕迹.当传送带沿逆时针方向匀速运动时,小物块无初速地放在A点,运动至B

点飞出.要想使小物块在传送带上留下的痕迹最长,传送带匀速运动的速度v至少多大?g取l0m/s2

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