钳型电流表的钳口必须钳在有绝缘层的导线上，同时要与其他带电部分保持足够的安全距离，防

关于细胞因子的叙述，下列哪项是错误的（）

A.由细胞合成和分泌的生物活性物质

B.能调节多种细胞的生理功能

C.在免疫系统中起着非常重要的调控作用

D.无论在什么情况下对机体都是有利的

E.细胞因子包括IL、IFN、CSF、TNF和趋化因子

正态均值法需要计算患者数据的（）

A.均值

B.标准差

C.标准误

D.变异系数

E.均值和标准差

酿酒用的葡萄，果皮中含有（）和（）两种有效物质。

当机件不对称，又要同时表示内外形状，应采用（）。

A、全剖视；

B、半剖视；

C、局部剖视

Losing a job or not being able to find one almost always brings unwelcome changes. If you’’ve lost a job, the first feeling is often one of shock. On top of the loss of income, many people find the whole routine of their life is shattered, their contact with other people reduced, their ambitions halted and their identity as a worker removed.There may be good feelings too — it’’s nice to be able to lie in bed in the morning, to spend more time with children, or to have more time to think — a better job may be just around the corner. But, unless a better job does turn up, chances are the days start getting longer and the time becomes harder to fill. Many people pass through periods of difficulty in sleeping and eating. They feel irritable and depressed, often isolated and lonely.Despite all these problems, unemployment can be a chance for a fresh start. You can discover that it provides an opportunity to sort out or rethink what you want from life and how best you can get it. You can use the time to plan how to find a new job, learn a new skill, develop your hobbies, see if you can run your own business, do some voluntary work in your community or meet new people. It’’s up to you.

The unemployed become finally disillusioned when they________.

A．have nothing more to think about

B．are unable to improve their position

C．get tired of playing with their children

D．can no longer lie in bed in the morning