Official23 托福阅读Passage1Urban Climates文本+题目原文+答案解析【雷哥托福】2019-02-22 11:58:29 发布 来源：雷哥托福
TPO23 托福阅读Passage1Urban Climates文本+题目原文+答案解析
The city is an extraordinary processor of mass and energy and has its own metabolism. A daily input of water, food, and energy of various kinds is matched by an output of sewage, solid waste, air pollutants, energy, and materials that have been transformed in some way. The quantities involved are enormous. Many aspects of this energy use affect the atmosphere of a city, particularly in the production of heat.
In winter the heat produced by a city can equal or surpass the amount of heat available from the Sun. All the heat that warms a building eventually transfers to the surrounding air, a process that is quickest where houses are poorly insulated. But an automobile produces enough heat to warm an average house in winter, and if a house were perfectly insulated, one adult could also produce more than enough heat to warm it. Therefore, even without any industrial production of heat, an urban area tends to be warmer than the countryside that surrounds it.
The burning of fuel, such as by cars, is not the only source of this increased heat. Two other factors contribute to the higher overall temperature in cities. The first is the heat capacity of the materials that constitute the city, which is typically dominated by concrete and asphalt. During the day, heat from the Sun can be conducted into these materials and stored—to be released at night. But in the countryside materials have a significantly lower heat capacity because a vegetative blanket prevents heat from easily flowing into and out of the ground. The second factor is that radiant heat coming into the city from the Sun is trapped in two ways: (1) by a continuing series of reflection among the numerous vertical surfaces that buildings present and (2) by the dust dome, the cloudlike layer of polluted air that most cities produce. Shortwave radiation from the Sun passes through the pollution dome more easily than outgoing longwave radiation does; the latter is absorbed by the gaseous pollutants of the dome and reradiated back to the urban surface.
Cities, then, are warmer than the surrounding rural areas, and together they produce a phenomenon known as the urban heat island. Heat islands develop best under particular conditions associated with light winds, but they can form almost any time. ■The precise configuration of a heat island depends on several factors. ■For example, the wind can make a heat island stretch in the direction it blows. ■When a heat island is well developed, variations can be extreme; in winter, busy streets in cities can be 1.7℃ warmer than the side streets. ■Areas near traffic lights can be similarly warmer than the areas between them because of the effect of cars standing in traffic instead of moving. The maximum differences in temperature between neighboring urban and rural environments is called the heat-island intensity for that region. In general, the larger the city, the greater its heat-island intensity. The actual level of intensity depends on such factors as the physical layout, population density, and productive activities of a metropolis.
The surface-atmosphere relationships inside metropolitan areas produce a number of climatic peculiarities. For one thing, the presence or absence of moisture is affected by the special qualities of the urban surface. With much of the built-up landscape impenetrable by water, even gentle rain runs off almost immediately from rooftops, streets, and parking lots. Thus, city surfaces, as well as the air above them, tend to be drier between episodes of rain; with little water available for the cooling process of evaporation, relative humidities are usually lower. Wind movements are also modified in cities because buildings increase the friction on air flowing around them. This friction tends to slow the speed of winds, making them far less efficient at dispersing pollutants. On the other hand, air turbulence increases because of the effect of skyscrapers on airflow. Rainfall is also increased in cities. The cause appears to be in part greater turbulence in the urban atmosphere as hot air rises from the built-up surface.
TPO23 托福阅读 Passage1 Urban Climates 题目
Question 1 of 14: The word “enormous” in the passage is closest in meaning to
C. very large
D. strictly controlled
Question 2 of 14: The word “surpass” in the passage is closest in meaning to
A. remain below
B. be higher than
C. add to
D. come close to
Question 3 of 14: According to paragraph 2, how soon heat from a warmed house reaches the outside air greatly affected by
A. how well the house is heated
B. how well the house is insulated
C. how many adults live in the house
D. how much sunshine the house receives
Question 4 of 14: According to paragraph 3, each of the following contributes to making urban areas warmer than the surrounding countryside EXCEPT
A. the fuel burned by motor vehicles
B. the capacity to store heat of the materials used in building a city
C. the easy flow of heat into the ground in city areas covered by vegetation
D. the repeated reflection of solar radiation back and forth among buildings
Question 5 of 14: According to paragraph 3, why do materials in the countryside have a lower heat capacity than materials in cities do?
A. In the countryside in the Sun is the only important source of heat.
B. Construction materials in the city are not as good at keeping buildings warm as they are in the countryside.
C. In the countryside the solar heat that flows into the ground flows out again quickly.
D. Countryside vegetation prevents heat from being trapped in the ground.
Question 6 of 14: How is paragraph 3 organized?
A. It describes two factors that contribute to the increased heat of cities and then provides two causes for the second factor.
B. It describes two causes discovered in an early analysis of the increased heat of cities.
C. It describes two factors that contribute to the increased heat of cities and two other factors that work against it.
D. It describes two well-established causes of the increased heat of cities and other two whose roles are less well understood.
Question 7 of 14: The word “configuration” in the passage is closest in meaning to
Question 8 of 14: According to paragraph 4, what can explain the substantial differences in temperature between one area and other within a well-developed heat island?
A. The overall size of the heat island that includes the two reasons
B. The intensify of the heat island that includes the two areas
C. Differences between the two areas in the general level of activity, including traffic
D. Differences between the two areas in the insulation materials used in construction
Question9 of 14: Paragraph 4 supports the idea that a city’s heat-island intensity would increase if
A. the city went into an economic decline and lost population
B. the city’s economy shifted from heavy industry to health care and education
C. there was an upward trend in the average age of the city’s residents
D. repair work on the streets slowed traffic throughout the city
Question10 of 14: According to paragraph 5, surfaces in the city are generally drier than surfaces in the countryside between periods of rainfall because
A. in the city gentle rain is much more common than heavy rain
B. high temperatures in the city speed up the process of evaporation
C. in the city there are longer periods of dry weather between episodes of rain
D. rainwater in the city cannot soak into most surfaces and quickly runs off
Question11 of 14: The word “modified” in the passage is closest in meaning to
Question 12 of 14: According to paragraph 5, which of the following is a factor responsible for the greater air turbulence in urban environments?
A. The high speed of the winds travelling above cities
B. The greater rainfall totals recorded in cities
C. Attempts to reduce urban air pollution
D. The effects of tall buildings on airflow
Question13 of 14: Look at the four squares [■] that indicate where the following sentence could be added to the passage.
Another possibility is for the heat island to be stretched along the course of major rivers, since large waterways typically have a warming effect on the air directly above them.
Where would the sentence best fit?
A. The precise configuration of a heat island depends on several factors.
B. For example, the wind can make a heat island stretch in the direction it blows.
C. When a heat island is well developed, variations can be extreme; in winter, busy streets in cities can be 1.7℃ warmer than the side streets.
D. Areas near traffic lights can be similarly warmer than the areas between them because of the effect of cars standing in traffic instead of moving.
Question14 of 14: Cities create climatic conditions of their own through their physical structure and urban activities.
A. The amount of heat produced in a city will be reduced when cities use the heat from cars to warm homes.
B. The built-up landscape of the city readily becomes a heat island, with greater water runoff and special climatic conditions such as low relative humidity and increased air turbulence.
C. The materials from which cities are built and the effects of pollution domes help make urban areas warmer than rural areas.
D. Cities tend to be warmer than their surrounding areas, in part because they produce heat by burning fuel for heating, powering vehicles, and industrial production.
E. In most cities, the heating that results from solar radiation is intensified by carbon dioxide, a gas that is present at very high concentrations in cities’ atmospheres.
F.During periods without rainfall, the air in cities heats up and causes winds to slow down, with the result that pollutants are not dispersed.
TPO23托福阅读Passage1Urban Climates 真题解析
Question 1 of 14:
解析： enormous“巨大的”，所以正确答案是C的very large。单词所在句的前句说城市的物质和能量的输入和输出的废水、空气污染物、物质和能量是相当的，接着这句话提到这一过程涉及的物质的量是怎么样的，对于一个城市来说，输入和输出的物质的量当然都很大，所以答案是C，A“增长”B“令人恐惧的”D“被严格控制的”都不合文意。
Question 2 of 14:
解析：surpass“超过”，所以正确答案是be higher than。从单词本身看，sur表示“加强”，pass表示“过”，所以合在一起表示“超过”之意。原句说冬天城市里产生的热量可以等于或者怎么样太阳提供的热量，跟等于并列的要么是多于要么是少于，所以正确答案是B。
Question 3 of 14:
解析：以warmed house和outside air做关键词定位至第二句，提到当房间隔热差的时候，热量散失最快，所以散失的快慢应该取决于房屋的隔热状况，所以正确答案是B，其他答案都未提及。
Question 4 of 14
解析：此题可以采用排除法。A的motor vehicles做关键词定位至第一句的cars，说fuel燃烧不是唯一来源，所以A正确，不选；B 的capacity做关键词定位到第三句，也正确，不选；C的vegetation做关键词定位至第五句，说的是countryside，没说城市，所以C错误，选；D的reflection做关键词定位至两个ways的第一个，也是正确的，不选。
Question 5 of 14
解析：以lower heat capacity做关键词定位至第五句，提到农村的heat capacity低于城市是因为植被覆盖使得heat不那么容易进入或者流出地表，所以正确答案是D。A的only source，B的construction materials都没未提及，C与原文相反，原文说不那么容易。
Question 6 of 14
解析：提问整段的，可以先看看开头1-2句。首句提到机动车不是唯一因素，第二句说还有两个其他的因素，然后后文详细叙述了这两个因素都是什么，所以正确答案是A。B的early analysis，C的work against it和D的less well understood都未提及，而且A特别提到了two causes for the second factor。
Question 7 of 14
Question 8 of 14
解析：以difference和well-developed heat island双关键词定位至第五和第六句，说well developed的热岛里的变化是非常大的，在冬天，繁忙街道可以比不繁忙的高1.7度，后来又提到信号灯所在的位置比没有信号灯的位置热，都在说交通，所以C是正确的，提到城市的繁忙情况，包括交通。A的size，B的intensity和D的insulation materials都未提及。
Question 9 of 14
解析：以intensity做关键词定位至倒数三句，提到城市越大intensity越强，还取决于layout，population density和productive activity，所以正确答案是D，而且也可以根据上一题得出这个答案。A与原文相反，如果population少intensity应该下降；B的shift和C的age都未提及。
Question 10 of 14
解析：以rainfall做关键词定位至第三句，提到城市的建筑大多是不透水的，即使是最小的雨也会流走，这是城市地表干燥的原因，所以正确答案是D。A的gentle rain much more common，B的speed up和C的longer periods of dry weather原文都未提及，不选。
Question 11 of 14
Question 12 of 14
解析：以air turbulence做关键词定位至倒数第三句，提到air turbulence增加是因为高层建筑影响气流，所以正确答案是D。A的high speed，B的rainfall和C的air pollution原文都未提及，不选。‘
Question 13 of 14
解析：这一题相对简单，代词another可以作为过渡点，由于是anther example，所以之前必须有一个例子，所以可以初步确定正确答案是C。带进去检验，stretched along the course of major rivers与后面的When a heat island is well developed也是衔接的，所以可以确定C答案。
Question 14 of 14
解析：A选项说当城市使用汽车产生的热量来家庭供暖时，城市产生的热量会减少，此内容原文未提及，不选；B选项说城市的建筑物容易成热岛，因为大量的水都run off 了，对应原文第五段的内容，正确；C选项说城市的建筑材料及污染物的排放使得城市比农村温度高，对应原文第三段前部分的内容内容，正确；D选项对应原文整个第三段，正确；E选项中的carbon dioxide原文未提及，不选；F选项中的without rainfall原文未提及，不选。所以正确答案为BCD。