Tornadoes, whirlwinds, and watersprouts are rotating funnel cloud air masses

游客2023-09-14 40

问题 Tornadoes, whirlwinds, and watersprouts are rotating funnel cloud air masses of small diameter. They are differentiated by the intensity of their rotation and by the surfaces that they traverse. Though tornadoes and whirlwinds both travel over land masses, whirlwinds are atmospheric systems smaller than tornadoes. Watersprouts are tornadoes that form or pass over a water surface. A tornado is a powerful vortex or "twister" whose rotational speeds are estimated to be near 300 miles per hour. The first visible indication of tornado development is usually a funnel cloud. As this funnel dips earthward, it becomes darker because of the debris that is forced into its intensifying vortex. Some tornadoes give no visible warning Until their destruction strikes the unsuspecting victim. Tornadoes often occur in groups, and several twisters sometimes descend from the same cloud base. The forward speed of a tornado is normally 30 to 40 miles per hour. In the short time that it takes to pass, a tornado can cause fantastic destruction. There have been cases reported in which blades of straw were embeded in fence posts. [br] The author refers to straw embeded in fence posts in order to show ______.

选项 A、where tornadoes occur
B、who makes reports about tornadoes
C、when tornadoes take form
D、how tornadoes affect physical objects

答案 D

解析这道题要求考生进行分析。前面文中提到龙卷风能造成巨大破坏，然后提到龙卷风使稻草嵌入栅栏柱上的例子，作者的意图当然是要强调龙卷风在物体上作用有多么强大，所以四个选项中很容易找出正确答案。

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Tornadoes, whirlwinds, and watersprouts are rotating funnel cloud air masses

【B1】[br]【B13】A、revolvingB、stirringC、mixingD、rotatingB因为河堤很坚固，所以船行驶时激起的水才不会

【B1】[br]【B13】A、revolvingB、stirringC、mixingD、rotatingB砖块、石头和水泥可使岸堤坚固，因此即使水面