搜题请搜索小程序“爱下问搜题”
问题 问答题 简答题

什么是系统误差，它是怎样产生的，如何消除？

答案

参考答案：

系统误差是在一定的条件下，一种有规律的，重复出现的误差，在每次测定中，此误差总是偏向某一个方向，其大小几乎是一个恒定的数，所以系统误差也称为恒定误差

单项选择题

患者男，18岁，被人殴打后胸痛，结合胸片，最可能的诊断是（）

A.血气胸

B.气胸

C.胸腔积液

D.肺气肿

E.肺挫伤
查看答案
填空题

British people are far more sophisticated about beverages than they were 50 years ago. Witness the Starbucks revolution and you’ll know where (1) goes. However, spurred on by recent studies suggesting that it can cut the risk of (2) and retard the aging process, tea is enjoying a (3) .

Although tea is available in more places than ever, it remains to be (4) of a typical British family.

If you are invited to an English home, (5) in the morning you get a cup of tea. It is either brought in by a heartily (6) or an almost malevolently silent maid. When you are (7) in your sweetest morning sleep you must not say: "Go away, you (8) ." On the contrary, you have to declare with your best five o’clock smile. "Thank you very much. I (9) a cup of tea, especially in the morning." If they leave you alone with the liquid you may pour it (10) !

Then you have (11) ; then you have tea at 11 o’clock in the morning; (12) ; then you have tea for tea; then after supper; and again at eleven o’clock (13) .

You must not refuse any additional cups of tea under the(14) if it is hot; if it is cold; if you are (15) ; if you are nervous; if you are watching TV; (16) ; if you have just returned home; if you feel like it; if you do not feel like it; if you have had no tea (17) ; if you have just had a cup.

You definitely must not (18) . I sleep at five o’clock in the morning; I have coffee for breakfast; I drink innumerable (19) during the day; I have the (20) even at tea-time!

6（）
查看答案