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问题 选择题

关于匀速直线运动的速度 ，下列讨论正确的说法是（       ）

A．物体运动速度v越大，通过的路程s越长

B．物体运动速度v越大，所用时间t越少

C．v的大小由s/t决定，但与s、t的大小无关

D．上述说法都正确

答案

答案：C

A答案中没有确定时间，准确应该说在单位时间内，物体的速度越大，通过的路程就越大，B选项中没有确定路程，应该说是在路程相同的情况下，物体的速度越大所用的时间t就越少，答案C是速度的定义，单位时间内通过的路程的多少

填空题


Motivation is "the driving force within individuals that impels them to action." And goals are the sought-after results (1) motivated behavior.
Motivation can be either positive or negative (2) direction. We may feel a driving force toward some object or condition, (3) a driving force away from some object or condition. For example, a person may be impelled toward a restaurant to fulfill a need, hunger, and away (4) an airplane to fulfill a need of safety. Some psychologists refer to positive drives (5) needs, wants or desires, (6) negative drives as fears or aversions (7) , though negative and positive motivational forces seem to differ dramatically (8) terms of physical and sometimes emotional activity, they are basically similar in (9) they both serve to initiate and sustain human behavior. (10) this reason, researchers often refer (11) both kinds of drives or motives as needs, wants and desires.
Goals, (12) , can be either positive or negative. A positive goal is one toward (13) behavior is directed and it is often referred to as an approach object. A negative goal is (14) from which behavior is directed away and it is sometimes referred to as an avoidance object. Since both approach and avoidance goals can be considered objectives of motivated behavior, most researchers refer to (15) types simply as goals. Consider this example. A middle-aged woman may wish to remain (16) attractive as possible. Her positive goal is to appear desirable, and (17) she may use a perfume advertised to make her irresistible. A negative goal may be to prevent her skin (18) aging, and therefore she may buy and use face creams. (19) the former case, she uses perfume to help her achieve her positive goal -- attractiveness; in the (20) case, she uses face creams to help avoid a negative goal -- wrinkled skin.
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单项选择题

关于 Unix 操作系统的特性，以下哪种说法是错误的？

A．Unix 是一个支持多任务、多用户的操作系统

B．Unix 本身由 Pascal 语言编写、导读、易移植

C．Unix 提供了功能强大的 Shell 编程语言

D．Unix 的树结构文件系统有良好的安全性和可维护性
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