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问题 选择题

将一瓶酒精用去三分之二，则剩余部分酒精的质量、比热容和热值（　　）

A．都变为原来的三分之一

B．热值、比热容不变，质量变为原来的三分之一

C．都不变

D．热值不变，质量、比热容变为原来的三分之一

答案

①比热容是物质的一种特性，各种物质都有自己的比热，某种物质的比热容和其质量、体积、温度无关，所以将一瓶酒精用去三分之二，比热容不变，质量变为原来的三分之一；

②燃料的热值是燃料的一种特性，与燃料的质量、温度和体积无关，所以将一瓶酒精用去三分之二，剩下的酒精的热值不变，比热容、燃料的热值都是物质的特性，它们的大小与物体的质量和体积均无关系，故选项A、C、D错误，B正确．

故选B．

单项选择题

下列不属于商业银行产品线的是( )。

A．公开市场业务
B．支付和结算
C．零售银行业务
D．资产管理
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单项选择题

Like all the huge metropolises of the world, there are lots of diversions both outdoors and indoors in Chicago. The Art Institute of Chicago has one of the world’s (1) art collections, including more French Impressionist paintings than even in the Paris Louvre itself. The Field Museum of Natural History and the Museum of Science and Industry are also great historical and cultural treasure houses to (2) as well as entertain children and adults (3) In the Field Museum one comes (4) a surprisingly big collection of Chinese exhibits from the ancient (5) to the early century. The Sears Tower and the Buckingham Fountain are the pride of the Chicagoans; (6) having 110 storeys is said to be the highest tower in the world and the (7) is the largest fountain in the United States. Lake Michigan is for yachting in summer time, (8) the highlights of Chicago life all the year round are concerts, operas and plays (9) by the city’s orchestra, opera houses and theatres. In summer, especially around the Independence Day, July 4th, many festivals and fairs are given outdoors, which, (10) crowds and crowds of people, with their parades, fireworks, (11) concerts, water-skiing and good foods.

But with all its attractions and beautiful spots Chicago is also a city (12) for crimes. All the dwelling houses are (13) with three doors and visitors have to speak through microphone (14) in the wall to the residents before they can get admitted. In the streets there are white-color telephones. When one finds oneself (15) , he needs only to knock the receiver (16) the hook and the next instant the police will (17) . If one does not drive a car, it may well be dangerous for him or her to go out alone in the evening. At first I did not take this warning seriously. (18) , my two encounters with the Black people (19) dusk in the neighborhood were so unpleasant and frightening that I have (20) shut myself evenings in my room, in almost all studying, imposing a curfew on myself.

17（）

A. rescue him

B. come to his rescue

C. come to save

D.save
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