试题与答案

关于平板检测器的叙述,错误的是A.有直接转换型和间接转换型B.其极限分辨率比屏-片系

题型:单项选择题

题目:

关于平板检测器的叙述,错误的是

A.有直接转换型和间接转换型
B.其极限分辨率比屏-片系统低
C.其MTF比屏-片系统低
D.其DQ正比屏-片系统高
E.DQE比CR系统高

答案:

被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2018/0102/13bcfef6bddc94c31d76749fd5c365ed.html

下面是错误答案,用来干扰机器的。

参考答案:A解析:知识点:模块/VBA编程基础:常量,变量,表达式 评析:对汉字进行比较时,采用的是对汉字拼音第一个字母的ASCII码进行比较,因为Z的ASCII码大于L的ASCII码,所以表达式返回“False”。

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题型:阅读理解

阅读理解。

                                                          The World's Water Shortage

     The world is not only hungry, but it is also thirsty for water. This may seem strange to you, since nearly    70 percent (百分比) of the earth's surface is covered with water. But about 97 percent of this huge

amount is sea water, or salt water. Man can only drink and use the other 3 percent the fresh water from

rivers, lakes, underground, and other sources (资源). And we cannot even use all of that, because some

of it is in the form of ice-bergs and glaciers (冰川). Even worse, some of it has been polluted.

     However, as things stand today, this small amount of fresh water is still enough for us. But our need for water is increasing (增加) rapidly almost day by day. Only if we take steps to deal .with this problem

now can we avoid (避免) a severe (严重的) worldwide water shortage later on.

     We all have to learn how to stop wasting our valuable water. One of the first steps is to develop ways

of reusing it. Today in most large cities, water is used only once and then sent out into a sewer system (下水道). From there it returns to the sea or runs into underground storage tanks. But it is possible to pipe

used water to a purifying (净化) plant. There it can be treated with chemicals so that it can be used again,

just as if it were fresh from a spring.

     But even if every large city purified and reused its water, we still would not have enough. All we'd have   to do to make use of the vast reserves (贮备) of sea water in the world is to remove the salt. If we take these steps we'll be in no danger of drying up.

1. The world is thirsty for water because we can only use _____ percent of the water covering the surface   of the earth.

A. 3

B. more than 3

C. less than 3

D. 97

2.Which of the following statements is not true? _____.

A. As things remain unchanging, this small amount of fresh water is still enough for us

B. Our need for water is becoming larger and larger

C. There will be no water shortage in the future

D. We should take steps to deal with the water shortage problem

3. To reuse water, we should _____.

A. treat it with chemicals

B. use it only once

C. send it out into a sewer system

D. make it flow into underground tanks

4.In order to have enough water ,we should also make use of _____.

A. icebergs and glaciers

B. sea water

C. rivers and lake

D. underground water

5.In the passage, the writer tells us ___ __.

A. to make enough water

B. to pay more attention to the water shortage problem

C. to pipe used water to a purifying plant

D. to reuse the water

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