小练(开双).docVIP

泗阳中学冲刺小练（八） 阅读理解（共15小题;每小题2分，满分30分） 阅读下列短文，从每题所给的四个选项（A、B、C和D）中，选出最佳选项，并在答题卡上将该项涂黑。 A 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. 56. 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. 57. As water gets colder after reaching t