问题 单项选择题 A1/A2型题

下列窗宽的概念正确的是()

A.通常CT机的窗宽都是固定的

B.窗宽规定了所显示CT值的范围

C.窗宽规定了所显示灰阶的中线

D.窗宽越大,组织的对比分辨率越高

E.窗宽包括所有组织的显示范围

答案

参考答案:B

解析:窗宽指图像上16个灰阶所包括的CT值范围,在此范围内的组织均以不同的模拟灰度显示,大小直接影响图像的对比度。窗位指应选择欲观察组织的CT值为中心,它的高低影响图像的亮度。窗宽与窗位的选择,关系到组织结构细节的显示,如果选择不当,易导致图像结构显示不清,严重者甚至不能满足诊断要求。

阅读理解

阅读表达。

     While it is impossible to live completely free of stress (压力), it is possible to prevent stress as well as

reduce its effect when it can't be avoided. The US Department of Health and Human Services offers the

following suggestions for ways to deal with stress.

     Try physical activity

     When you are nervous, angry or upset, try releasing (释放) the pressure (压力) through exercise or

physical activity. Running, walking, playing tennis and working in your garden are just some of the activities

you might try.

     Take care of yourself

     You should make every effort to eat well and get enough rest. If you easily get angry and cannot sleep

well enough, or if you're not eating properly, it will be more likely that you will fall into stressful situations.

If stress repeatedly keeps you from sleeping, you should go to see a doctor.

     Make time for yourself

     Schedule time (确定时间) for both work and entertainment. Don't forget, play can be just as important

to your well-being (幸福) as work. You need a break from your daily routine (日常事务) to just relax and

have fun. Go window-shopping or work on a hobby. Allow yourself at least a half hour each day to do

something you enjoy.

     Make a list of things to do

     Stress can result from disorganization and a feeling that "there's so much to do,and not enough time".

Trying to take care of everything at once can be too much for you and as a result, you may not achieve

anything. Instead, make a list of everything you have to do, then _____, check off each task as it is

completed. Set out to do the most important tasks first.

1. What is the best title of the passage? (Please answer within 10 words.)

    _______________________________________________________________________________________

2. Which sentence in the passage can be replaced by the following one? You might feel stressed as a result

    of bad temper, poor quality of sleep or diet.

    _______________________________________________________________________________________

3. Please fill in the blank in the last paragraph with proper words or phrases to complete the sentence. (Please

    answer within 10 words.)

    _______________________________________________________________________________________

4. Which of the suggestions do you think is the best for you? Why? (Please answer within 30 words.)

    _______________________________________________________________________________________

5. Translate the underlined sentence in the last paragraph into Chinese.

    _______________________________________________________________________________________

多项选择题