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问题 单项选择题

从古到今，人类共经历了五次信息技术的重大发展历程，目前正处于的阶段是______。

A．语言的产生和应用
B．计算机技术和通信网络技术的普及应用
C．电报、电话、广播、电视的发明和普及应用
D．印刷术的发明

答案

参考答案：B

解析：从古至今，人类共经历了五次信息技术的重大发展历程，依次是：语言的使用 文字的出现和使用—印刷术的发明和使用—电话、广播、电视的发明和普及应用—计算机技术和通信网络技术的普及应用。因此本题选B。

多项选择题

近代警察与古代警察的主要区别包括( )

A．近代警察的职能是独立的，警察职能主要集中于警察机关。古代警察的职能尚未能集中于一个统一的专门机关，而是由行政官吏、军队、审判机关分别行使的

B．近代警察从中央到地方形成专职的警察队伍，成为国家庞大的专政工具之一，行使专门职权。古代警察则军警不分，警政合一，没有专门的组织

C．近代警察强调法制，警察机关的建立及其体制和职权，均以宪法或法律为依据。古代警察执法极不严格，私刑普遍存在

D．近代警察有统一的制式服装，古代警察则没有专门的服装
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单项选择题

A Special Clock Every living thing has what scientists call a biological clock that controls behavior. The biological clock________(51) plants when to form flowers and when the flowers should open. It tells insects when to __________(52) the protective cocoon (防护卵袋) and fly away, and it tells animals and human beings when to eat, sleep and wake.Events outside the plant and animal__________(53) the actions of some biological clocks . Scientists recently found, for example, that a tiny animal changes the color of its fur because of the __________(54) of hours of daylight. In the short_________(55) of winter, its fur becomes white. The fur becomes gray brown in _________(56) in the longer hours of daylight in summer.Inner signals control other _________(57) clocks. German scientists found that some kind of internal clock seems to order birds to begin their long migration_________(58) twice each year. Birds _________(59) from flying become restless when it is time for the trip, _________(60) they become calm again when the time of the flight has ended.Scientists say they are beginning to learn which _________(61) of the brain contain biological clocks. An American researcher, Martin Moorhead, said a small group of cells near the front of the brain__________(62) to control the timing of some of our actions. These __________(63) tell a person when to wake, when to _________(64) and when to seek food. Scientists say there probably are other biological clock cells that __________(65) other body activities.

A．days

B． months

C．minutes

D．weeks
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