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问题 选择题

下列几个生活场景中，通过做功改变物体内能的是（     ）

A．冬天晒太阳，身体感到暖和

B．冬天搓手，手感到暖和

C．冬天对着手“哈气”，手感到暖和

D．冬天围着火炉取暖，身体感到暖和

答案

答案：B

题目分析：改变内能的方法有两种：做功和热传递，它们在改变物体内能上是等效的。做功改变内能的实质是其它能转化为内能，是能量的转化过程；热传递可以改变物体的内能，它的实质是内能的转移．

A、晒太阳是把太阳能转移到身上，是通过热传递的方式改变物体内能的，不符合题意；

B、搓手时两手摩擦做功，机械能转化为内能，手的内能增加，温度升高，是通过做功改变内能的，符合题意；

C、对手“哈气”时，“哈气”的温度高，手的温度低，是通过热传递的方式改变物体内能的，不符合题意；

D、火炉取暖是通过热传递的方式改变物体内能的，不符合题意；故选B．

单项选择题

Questions from 36 to 40 are based on the following passage: There are a lot of “markets”. Some markets are local; you may be willing to compare prices for fruits and vegetables in a few shops in your local area, but you would be unwilling to go across the city to find out more information. Some markets are national. Many firms sell goods across the country. Some markets are global or international. Increasingly, more and more countries are involved in the world economy, whether they know about it or not.However, there are many other markets: labor markets for job seekers, supermarkets for grocery shopping, foreign exchange market, capital market, real estate markets and so on. And we must not overlook the fact that many services such as banking, insurance are also bought and sold on a worldwide scale. But what is a “market” Most people would say, “A market is a place where enough buyers and sellers meet face to face, so that a market price for goods and services can be determined.” However, with rapid growth of telecommunications, it is no longer necessary for buyers and sellers to physically meet to form a market.You may hear the terms “global market” or “global economy”. What do those terms mean to you What do they mean to business today Thanks to the Information Age we are seconds away from the rest of world. Business everywhere recognizes that they can expand their market to anywhere and do business at any time because of the Internet. Now, the Internet is the fastest growing market in the world today, yet buyers and sellers don’t even have to leave their own homes to transact business.In the modern world, a market can take many forms. Generally speaking, a market may be housed in a place, or it may exist only in people’s minds. And a market can be any place or process that brings together buyers and sellers with a view to agreeing to a price.

Which of following markets is not mentioned in the passage （）

A．Asian market

B．international market

C．national market

D．local market
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单项选择题

将偏离或缺少的质量特性或质量要素称为（）。

A.不合格项

B.合格项

C.成品要素

D.半成品要素
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