TOEFL Questions
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CLI 아카데미
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2020-03-19 13:13
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Tornadoes
A tornado is a violent, funnel-shaped storm. Often accompanied by high winds and rain, tornados can cause massive destruction. For years, the danger of getting close to tornadoes made them difficult to study; however, with modern tools, scientists have learned more about their life cycle. Tornadogenesis is made up of four stages; supercell relationship, formation, maturation, and dissipation.
Most tornados originate as part of a supercell storm system, a type of thunderstorm featuring a rotating pocket of air that travels upward-an updraft. The rotating updraft is called a mesocyclone. During the storm, the mesocylcone travels several miles up in the atmosphere. Heavy rainfall drags down an area of rapidly descending air called the “rear flank downdraft,” or RFD. The RFD accelerates as it descends, dragging the supercell’s rotating mesocyclone with it.
As the mesocyclone gets closer to the ground, a condensation funnel descends from the storm. When the RFD touches the ground, it creates strong gusts capable of causing significant damage.
Within minutes of touching the ground, the funnel could becomes a tornado. It is fueled by warm, moist air, which allows it to mature. Some tornadoes grow for only a few minutes, but others can keep growing for up to an hour, which explains how some tornadoes get to be over a mile across. During maturation, the tornado is at its most dangerous. The RDF warps around the base of the tornado, blocking the inflow of warm air.
In the final stage, the RFD completely envelops the tornado, cutting off its air supply. Without warm air, the tornado cannot grow. The dissipation stage is usually short, and after the tornado has weakened, it is blown away by the winds in the supercell.
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Fennel : a tube-like object that is wide at one end and narrow at the other
Accompany: to be present or to occur with something
Tornadogenesis: the process by which a tornado forms
Dissipation: the act of breaking apart or scattering
Rotate: the act of breaking apart or scattering
Rotate: to turn in a circle
Descend: to move downward
Gust: a strong, brief wind
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Q. Which of the following best expresses the essential information in the highlighted sentence in paragraph 4? Incorrect answer choices change the meaning in important ways or leave out essential information.
(A) Tornados cannot grow large unless they have a long time to mature.
(B) The maturation stage can last between a minute and an hour, and when given the time to mature, tornadoes can become very large.
(C) Some tornadoes grow very large because they are in the maturation stage for a short period of time.
(D) A tornado takes only a few minutes to grow, and after an hour, it is very large.
A> (B) The maturation stage can last between a minute and an hour, and when given the time to mature, tornadoes can become very large.