敏感性分析常用的指标有（） A.现值 B.净现值 C.内涵报酬率 D.投资回收期

预乙级国际招标代理机构资格具有中级职称以上的专职招标人员不得少于从事招标业务人员总数的( )。

A．50%

B．60%

C．70%

D．80%

某铅冶炼工人张某，在单位组织的健康检查中，发现其血、尿中铅含量明显升高，并有贫血和轻度中毒性周围神经病变。单位安排他脱离铅作业，到职业病院进行疗养和驱铅治疗，该措施属于（）

A.高级预防

B.初级预防

C.一级预防

D.二级预防

E.三级预防

Most people feel lonely sometimes, but it usually lasts only a few minutes or a few hours．This kind of loneliness is not serious．In fact, it is quite normal．For some people, though, loneliness can last for years．Now researchers say there are three different kinds of loneliness．

The first kind of loneliness is temporary．This is the most common type．It usually disappears quickly and does not need any special attention．

The second kind, situational loneliness, is a natural result of a certain situation, for example, a family problem, the death of a loved one, or moving to a new place．Although this kind of loneliness can cause physical problems, such as headaches and sleeplessness, it usually does not last for more than a year．

The third kind of loneliness is the most severe．Unlike the second type, chronic （长期的） loneliness usually lasts more than two years and has no specific cause．People who experience habitual loneliness have problems socializing and being close to others．Unfortunately, many chronically lonely people think there is little or nothing they can do to improve their condition．

Psychologists agree that one important factor in loneliness is a person's social contacts, such as friends, family members, co-workers, etc．We depend on various people for different reasons．For instance, our families give us emotional support, our parents and teachers give us guidance, and our friends share interests and activities．However, psychologists have found that, though lonely people have many social contacts, they sometimes feel they should have more．They question then" own popularity．

Psychologists are trying to find ways to help habitually lonely people for two reasons: they are unhappy and unable to socialize and there is a connection between chronic loneliness and serious illness such as heart disease．While temporary and situational loneliness can be a normal and healthy part of life, chronic loneliness can be a very sad and sometimes dangerous condition．

小题1:Which of the following can be the cause of situational loneliness?

A．Sleeplessness．

B．Changing work．

C．Heart disease．

D．Social contacts．小题2:The underlined word "it" in the last sentence of the third paragraph refers to _____ ．

A．headaches

B．situational loneliness

C．sleeplessness

D．temporary loneliness小题3:How would you treat temporary loneliness according to the passage?

A．Just ignore it．

B．Talk to friends．

C．Go to see a doctor．

D．Ask your teachers for guidance．小题4:What can we learn from the passage?

A．People feel lonely in a certain situation．

B．There are only three types of loneliness in our life．

C．Loneliness doesn't affect people much．

D．Scientists have found ways to help habitually lonely people．

常温下，（）塑性最好

A、高碳钢

B、低碳钢

C、中碳钢

录井队应按照有关标准规定配置消防器材，设置消防安全标识，并定期检查、维护、保养。