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问题 填空题

在“研究匀变速直线运动”的实验中，如图为实验得到的一条纸带，纸带上每相邻的两计数点间的时间间隔均为0.1s，测得A到B和B到C的距离分别为5.60cm和7.82cm，则物体的加速度大小为______ m/s2，B点的速度大小为______m/s．

答案

根据运动学公式△x=at2得：

a=

△x
t2
=
xBC-xAB
t2
=
(7.82-5.60)cm
(0.1s)2
=2.2m/s2，

利用匀变速直线运动的推论得：

vB=

xAC
2t
=
(7.82+5.60)cm
0.2s
=0.671 m/s．

故答案为：2.22，0.671．

单项选择题

Modern liberal opinion is sensitive to problems of restriction of freedom and abuse of power. (1) , many hold that a man can be injured only by violating his will, but this view is much too (2) . It fails to (3) the great dangers we shall face in the (4) of biomedical technology that stems from an excess of freedom, from the unrestrained (5) of will. In my view, our greatest problems will be voluntary self-degradation, or willing dehumanization, as is the unintended yet often inescapable consequence of sternly and successfully pursuing our humanization (6) .

Certain (7) and perfected medical technologies have already had some dehumanizing consequences. Improved methods of resuscitation have made (8) heroic effort to "save" the severely ill and injured. Yet these efforts are sometimes only partly successful: They may succeed in (9) individuals, but these individuals may have sever brain damage and be capable of only a less-than-human, vegetating (10) . Such patients have been (11) a death with dignity. Families are forced to bear the burden of a (12) "death watch".

(13) the ordinary methods of treating disease and prolonging life have changed the (14) in which men die. Fewer and fewer people die in the familiar surroundings of home or in the (15) of family and friends. This loneliness, (16) , is not confined to the dying patient in the hospital bed. As a group, the elderly are the most alienated members of our society: Not yet (17) the world of the dead, not deemed fit for the world of the living, they are shunted (18) . We have learned how to increase their years, (19) we have not learned how to help them enjoy their days. Yet we continue to bravely and feverishly push back the frontiers (20) death.

5（）

A.advice

B.access

C.execution

D.exercise
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单项选择题

关于航空活塞发动机起动时注油的说法，正确的是：（）.

A.夏天注油多，冬天注油少

B.冬天注油多，夏天注油少

C.夏天和冬天注油一样多

D.夏天和冬天都不需要注油
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