题目:
管井井点的设备主要由井管、吸水管及()组成。
答案:
参考答案:水泵
管井井点的设备主要由井管、吸水管及()组成。
参考答案:水泵
Temperature is measured by means of a thermometer (温度计). One general form of thermometer depends upon the fact that most solids and liquids expand as their temperature rises. There are one or two exceptions. There is, for instance, a kind of steel called invar (from “invariable”) which does not change its dimensions as temperature changes; it is valuable for making pendulums (钟摆), since, if the length of a pendulum changes, its time of vibration changes. It is also used for making very accurate measuring scales. In both cases, then, changes of atmospheric temperature have no effect if invar is used.
Another exception is that very odd liquid, water, which has many strange properties (特性). As water gets colder it contracts (收缩), which is ordinary behavior, until it reaches the temperature of 30℃. above freezing point. After that, as it gets colder, it expands. This is fortunate---for considering the freezing of a pond. As the water on top gets colder, it shrinks; and so, volume for volume, it becomes heavier and sinks. This goes on until all the pond is at 30℃, but after that, as the water becomes colder it expands. Therefore the colder water stays on top and freezes, covering the pond with ice. If the water went on contracting down to the freezing point, the pond would become a solid block of ice in the end. This would not worry people who live in hot climates, but it would be very serious for those who live in cold climates, especially for those who want to break the ice and catch fish which live in the cold water beneath.
小题1: Invar is valuable for making pendulums because _______.
A.it can hardly change its shape or size as temperature changes.
B.it will change its dimensions without the change of temperature.
C.its time of vibration doesn’t change if its length changes.
D.its time of vibration does not change if its length changes.小题2: As water gets colder after reaching the temperature of 30℃. it will _______.
A.contract
B.shrink
C.expand
D.freeze小题3: Which of the following statements is true, according to this passage?
A.Only invar can be used to make a thermometer.
B.Only water can be used to make a thermometer.
C.Both invar and water can be used to make a thermometer.
D.Neither invar nor water can be used to make a thermometer.小题4:The best title of this passage is most likely to be _____.
A.Temperature Measurement
B.Two Exceptions
C.Uses of Invar
D.Properties of Water
研究制定建设项目投融资方案,应坚持的基本原则有()。
A.时机得当原则
B.依法融资原则
C.结构合理原则
D.规模适度原则
E.收益最大化原则
苯二氮革类药物的作用机制是()
A.抑制中枢神经细胞Cl- 通道,减少Cl- 细胞
B.抑制中枢神经细胞Na+通道,减少Na+流入细胞
C.影响中枢胆碱受体
D.影响中枢多巴胺受体
E.影响中枢γ-氨基丁酸受体
L市所在省份是劳务输出大省,农村出现大量留守儿童,为了更好地解决留守儿童学习生活等问题,政府拟进一步宣传寄宿制学校的办学模式。请根据“给定资料5”,以市教育局的名义草拟《给留守儿童家长的一封信》。
要求:
(1)内容具体,符合实际;
(2)用语得体,通俗易懂;
(3)400字左右。
在三种不同压缩过程中,压缩机所消耗功率最小的过程是()过程。
A.绝热压缩
B.等温压缩
C.多变压缩