问题
问答题 简答题
进行煤质分析所用的热电偶为什么要定期检定？
答案
参考答案：
热电偶在使用过程中，由于受到环境、周围介质和热的作用以及保护管和绝缘材料的污染等而使热电极出现氧化、腐蚀、晶体结构变化等现象。这些都会使热电偶的热电特性发生变化，因此须进行定期检定，否则会引起测量误差。
搜题请搜索小程序“爱下问搜题”
进行煤质分析所用的热电偶为什么要定期检定？
参考答案：
热电偶在使用过程中，由于受到环境、周围介质和热的作用以及保护管和绝缘材料的污染等而使热电极出现氧化、腐蚀、晶体结构变化等现象。这些都会使热电偶的热电特性发生变化，因此须进行定期检定，否则会引起测量误差。
| 阅读理解。 | |||||||||||||||||||||||||||
| Stress (压力) is everywhere in our everyday life. Not only men have it, but also women and young people. The most important reasons of stress are:death, diseases, exams, making money, getting married, moving houses, changing jobs, ending friendships and so on. How do you know whether you have stress? Could you give your answers to the following questions?
what can you do about it? Doing relaxing exercises, talking with friends and listening to light music are all usual ways of relieving (减轻) stress. However, doctors now say that there are easier ways-people should laugh and smile more often. When you laugh and smile, your body relaxes. They also say that people, especially men, should cry more often, be-cause crying is the natural way of relieving stress. | |||||||||||||||||||||||||||
| 1. If you have over ________ problems listed in the table, you are the person with stress. | |||||||||||||||||||||||||||
| A. two B. three C. four D. eight | |||||||||||||||||||||||||||
| 2. Which of the followings is NOT the reason of stress? | |||||||||||||||||||||||||||
| A. Taking exams. B. Watching films. C. Making money. D. Moving houses. | |||||||||||||||||||||||||||
| 3. What's the easier way to relax your body? | |||||||||||||||||||||||||||
| A. Talking with friends. B. Doing relaxing exercises. C. Laughing, smiling and crying. D. Listening to light music. | |||||||||||||||||||||||||||
| 4. The main idea of the passage is ________. | |||||||||||||||||||||||||||
| A. about stress and how to relieve your stress B. that there are many reasons for having stress C. that laughing and smiling more can help relieve your stress D. stress is everywhere in our everyday life |