收藏本页
免费课程咨询:400-801-6269(8:30-21:30)

托福考试网

当前位置: 托福 > 机经真题 >  真题回忆 >  文章

托福阅读考试真题及答案:PASSAGE 2

2016-12-22 14:17:19来源:坦途网资讯站分享

选择出国学习的人数越来越多,参加托福雅思考试无疑是进入国外大学的一块敲门砖。以下是坦途托福考试网小编整理的关于托福阅读真题及答案:PASSAGE 2,供大家练习备考。

The geology of the Earth's surface is dominated by the particular properties of water. Present on Earth in solid, liquid, and gaseous states, water is exceptionally reactive. It dissolves, transports, and precipitates many chemical compounds and is constantly modifying the face of the Earth.

Evaporated from the oceans, water vapor forms clouds, some of which are transported by wind over the continents. Condensation from the clouds provides the essential agent of continental erosion: rain. Precipitated onto the ground, the water trickles down to form brooks, streams, and rivers, constituting what are called the hydrographic network. This immense polarized network channels the water toward a single receptacle: an ocean. Gravity dominates this entire step in the cycle because water tends to minimize its potential energy by running from high altitudes toward the reference point, that is, sea level.

The rate at which a molecule of water passes though the cycle is not random but is a measure of the relative size of the various reservoirs. If we define residence time as the average time for a water molecule to pass through one of the three reservoirs atmosphere, continent, and ocean we see that the times are very different. A water molecule stays, on average, eleven days in the atmosphere, one hundred years on a continent and forty thousand years in the ocean. This last figure shows the importance of the ocean as the principal reservoir of the hydrosphere but also the rapidity of water transport on the continents.

A vast chemical separation process takes places during the flow of water over the continents. Soluble ions such as calcium, sodium, potassium, and some magnesium are dissolved and transported. Insoluble ions such as aluminum, iron, and silicon stay where they are and form the thin, fertile skin of soil on which vegetation can grow. Sometimes soils are destroyed and transported mechanically during flooding. The erosion of the continents thus results from two closely linked and interdependent processes, chemical erosion and mechanical erosion. Their respective interactions and efficiency depend on different factors.

1. The word "modifying" in line 4 is closest in meaning to

(A) changing

(B) traveling

(C) describing

(D) destroying

2. The word "which" in line 5 refers to

(A) clouds

(B) oceans

(C) continents

(D) compounds

3. According to the passage , clouds are primarily formed by water

(A) precipitating onto the ground

(B) changing from a solid to a liquid state

(C) evaporating from the oceans

(D) being carried by wind

4. The passage suggests that the purpose of the "hydrographic network" (line 8) is to

(A) determine the size of molecules of water

(B) prevent soil erosion caused by flooding

(C) move water from the Earth's surface to the oceans

(D) regulate the rate of water flow from streams and rivers

5. What determines the rate at which a molecule of water moves through the cycle, as discussed in the third paragraph?

(A) The potential energy contained in water

(B) The effects of atmospheric pressure on chemical compounds

(C) The amounts of rainfall that fall on the continents

(D) The relative size of the water storage areas

6. The word "rapidity" in line 19 is closest in meaning to

(A) significance

(B) method

(C) swiftness

(D) reliability

7. The word "they" in line 24 refers to

(A) insoluble ions

(B) soluble ions

(C) soils

(D) continents

8. All of the following are example of soluble ions EXCEPT

(A) magnesium

(B) iron

(C) potassium

(D) calcium

9. The word "efficiency" in line 27 is closest in meaning to

(A) relationship

(B) growth

(C) influence

(D) effectiveness

正确答案:AACCD CABD

托福培训课程免费试听

预约免费体验课您的信息不会显示在页面上或泄露给他人,我们将会通过电话反馈给您

课程预约 立即提交

免费课程咨询:400-801-6269        真道(北京)信息技术有限公司版权所有 京ICP备12044874号-1