问题 选择题

把体积大小相同的软木球和铜球投入水中,当它们在水中静止时,其所受浮力(  )

A.铜球大于木球

B.木球大于铜球

C.铜球等于木球

D.不能确定

答案

∵ρ>ρ>ρ

∴放入水中后,木球漂浮、铜球下沉,

∵铜球和木球体积相等,

∴铜球排开水的体积比木球排开水的体积大,

∵Fvg,

∴铜球受到水的浮力比木球受到水的浮力大,

故选A.

阅读理解

任务型阅读:阅读下面短文,并根据所读内容在文章后的空格里填入最恰当的单词。

     Without most people realizing it, there has been a revolution in office work over the last ten years. Before

that time, large computers were only used by large, rich companies that could afford the investment. With

the advancement of technology, small computers have come onto the market, which are capable of doing the

work that used to be done by much larger and expensive computers, so now most smaller companies can use

them.

     The main development in small computers has been in the field of word processors (处理器), or WPS as

they are often called. 40% of British offices are now estimated to have a word processor and this percentage

is growing fast.

     There are many advantages in using a word processor for both the secretary and the manager. The

secretary is freed from a lot of daily work, such as retyping letters and storing papers. He or she can use this

time to do other more interesting work for the boss. From a manager's point of view, secretarial time is being

made better use of and money can be saved by doing daily jobs automatically outside office hours.

     But is it all good? If a lot of daily secretarial work can be done automatically, surely this will mean that

fewer secretaries will be needed. Another worry is the increasing medical problems related to work with visual

display units (显示器). The case of a slow loss of sight among people using word processors seems to have

risen greatly. It is also feared that if a woman works at a VDU for long hours, the unborn child in her body

might be killed. Safe screens to put over a VDU have been invented but few companies in England bother to

buy them.

     Whatever the arguments for and against word processors, they are a key feature (特征) of this revolution

in office practice.

▲small computers:

▲l. __________ larger and expensive computers

▲2.__________ can use them.

Small computers have been 3._________ in the field of word processors, or WPS.

advantages

4.__________

▲The secretary:

●freed from a lot of 5._________

●do other more interesting work for the boss

▲6.__________

●secretarial time can be made better use of

●7._________ can be saved by doing daily jobs automatically outside office hours.

▲8._________ will lost their jobs.

▲medical problems related to work with visual display units

●Many people 9._________ slowly.

●The unborn child in its mother's body 10._________.

问答题 简答题