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问题 问答题

某课题小组进行探究活动．他们在塑料小桶中分别盛满已知密度的四种不同液体后，用弹簧测力计测出它们的重力，并将数据记录如下表：

液体的密度（g/cm3）0.81.01.21.4
弹簧测力计示数/N1.61.82.02.2
（1）分析此表，小倩发现液体的密度与弹簧测力计的示数之间有一定规律．能正确反映这一规律的图象是______（填“A”、“B”或“C”）．

（2）若小桶中盛满某种液体后，弹簧测力计的示数为2.3N，小倩推算出了该液体的密度是______多少kg/m3？（写出推算过程）

答案

（1）由于小桶有重力，所以小桶中没有东西时弹簧测力计也有示数，所以选项B符合，故选B；

（2）根据表中数据总结出的函数关系ρ=F-0.8，将F=2.3N代入得ρ=2.3-0.8=1.5g/cm3=1.5×103kg/m3，

故答案为：B；1.5×103．

单项选择题

The fact that most Americans live in urban areas does not mean that they reside in the center of large cities. In fact, more Americans live in the suburbs of large metropolitan areas than in the cities themselves.
The Bureau of the Census regards any area with more than 2,500 people as an urban area, and does not consider boundaries of cities and suburbs.
According to the Bureau, the political boundaries are less significant than the social and economic relationships and the transportation and communication systems that integrate a locale. The term used by the Bureau for an integrated metropolis is an MSA, which stands for Metropolitan Statistical Area. In general, an MSA is any area that contains a city and its surrounding suburbs and has a total population of 50,000 or more.
At the present time, the Bureau reports more than 280 MSAs, which together account for 75 percent of the U.S. population. In addition, the Bureau recognizes 18 megapolises, that is, continuous adjacent metropolitan areas. One of the most obvious megapolises includes a chain of hundreds of cities and suburbs across 10 states on the East Coast from Massachusetts to Virginia, including Boston, New York, and Washington D. C. In the Eastern Corridor, as it is called, a population of 45 million inhabitants is concentrated. Another megapolis that is growing rapidly is the California coast from San Francisco through Los Angeles to San Diego.

Why does the author mention the Eastern Corridor and the California coast in Paragraph 4

A．As examples of megapolises.

B．Because 75 percent of the population lives there.

C．To conclude the passage.

D．The Bureau of the Census is located ther
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问答题 简答题

纠风工作领导体制和工作机制的内容是什么？
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