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问题 问答题 简答题

什么是时钟周期？什么是总线周期？什么是指令周期？

答案

参考答案：时钟周期是CPU工作的时间基准，由计算机主频决定；

总线周期是CPU完成一次访问存储器或IO端口操作所需要的时间；

执行一条指令所需要的时间成为指令周期。

选择题

安装了空调的汽车，当空调开放时，车窗的玻璃上会出现一些水珠．下面说法正确的是（　　）

A．冬天水珠出现在窗玻璃内侧，夏天水珠出现在窗玻璃外侧

B．冬天水珠出现在窗玻璃外侧，夏天水珠出现在窗玻璃内侧

C．不论冬天还是夏天，水珠都出现在窗玻璃内侧

D．不论冬天还是夏天，水珠都出现在窗玻璃外侧
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填空题

Part 4


Questions 26-45


·Read the following passage and decide which answer best fits each space.
·Forquestions26-45, markoneletterA, B, C or D on the Answer Sheet.
Both (26) and zoology are parts of a more general field of science, biology. The two are studies of (27) things, which share certain characteristics, (28) they are plants or animals. Botany deals with plants, whose organisms that can (29) their own food by the use of sunlight. Zoology on (30) hand, deals with animals, those organisms that cannot manufacture their own food and are thus dependent (31) plants for their food.
(32) plants and animals share many abilities, the extent (33) which plants can exercise some of those abilities is (34) . For example, both plants and animals need food, water, and warmth for growth, (35) plants can move to (36) those needs only by the slow extraction of their leaves and roots, while animals can move relatively (37) distances in relatively little time. When an animal is hurt with needle, the animal will (38) the part of the body (39) . This ability to draw back (40) pain or irritation, called irritability, is found only to a very limited extent in plants.
If plants (41) the same (42) as animals, animals would have had a more difficult time finding food. If animals were as limited as plants, they might (43) a means of manufacturing their own food, as plants do now. The world would be a very different place (44) it is if the characteristics of plants and animals were (45)

A．But

B．Although

C．And

D．Furthermore
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