问题 选择题

下列不存在丁达尔效应的分散系是(  )

A.食盐水

B.稀豆浆

C.有尘埃的空气

D.向沸水中滴入FeCl3饱和溶液所得液体

答案

A.食盐水为溶液,不是胶体,不具有丁达尔效应,故A正确;

B.稀豆浆为胶体,具有丁达尔效应,故B错误;

C、有尘埃的空气属于胶体,存在丁达尔效应,故C错误;

D.向沸水中滴入FeCl3饱和溶液可得氢氧化铁胶体,存在丁达尔效应,故D错误.

故选:A.

阅读理解

阅读理解。

     LOS ANGELES--The advice offered from any other 82-year-old might have made young people yawn(打哈欠)and roll theft eyes.

     But when former South African President Nelson Mandela advised two dozen Los Angeles-area youth leaders to take education seriously, his audience was listening.

     The famed old man said to the young people that if they expected to improve the fives fives(一种游戏) of others in the future,they must work at improving their own fives now."Education is one of the most important weapons you have,"Mandela advised,"it will place you in a far better position to serve yourself and your community."

     "The point is,he was young once and rebellious(反叛的)once and he kept his dream alive,just as you each have dreams." Explained South Africa's ambassador to the United States,Sheita Sisulu,as she introduced Mandela to the young crowd.

     Asked for specific advice about changing society by 21-year-old Ahmed Younis,Mandela suggested that somehow helping arouse(唤醒)more American interest in foreign affairs might be a start.

    "There is an impression that Americans,in general,have not followed international developments properly,"Mandela said,"I'm not making that statement myself, but there are serious political analysts who say Americans are not well informed as to what has happened in the world."  

     22-year-old Omari Trice said Mandela left him full of passion."He's a person who set the tone(格调)for an entire nation."said Trice.

     "You go away feeling you need to be Superman in order to get things done."Trice said.

1.From the passage,we can conclude that American youth_____

A.are willing to accept the advice from world-famous leaders

B.usually think that advice from old people is not worth considering

C.have a good understanding of the old

D.have no intention to improve the fives of others

2.Nelson Mandela makes the point in his speech that American youth leaders should_____

A.improve their own fives   

B.go to college for better education

C.put more importance on education

D.become interested in foreign affairs

3.What Sheila Sisulu said suggested that      

A.Nelson Mandela never lost hope in his life

B.was especially troublesome when young

C.Nelson Mandela was quite different from American youth when young

D.American youth should be no more rebellious

4.From what Trice said,we can know that    

A.he was greatly impressed and encouraged by Mandela's speech

B.he thought little of Mandela's speech

C.he must be a superman in order to change society

D. he'll be more interested in international development

单项选择题

某出口加工企业为了保证出口产品质量,在生产线的最后增设一个技术水平较高的班组,专门负责检验和解决质量问题。但是,这种方法费用较高,且质量问题主要是由流水线上装配差错造成,因此,公司部分人员对这种方式感到不满,认为应当加以改革,以降低成本。
公司专门开会研究这个问题该如何解决。人事经理指出,车间的工作非常单调辛苦,所以工人对这种工作除了领取工资外,没有什么兴趣,造成工作中可能出现错误。因此,公司应该想办法提高工人的兴趣。所以,他建议公司做两件事:一是要工人掌握几种操作技能,而不是制作一项简单的动作;二是工人每星期轮流换班,从生产线的一个位置换到一个完全不同的位置,这样可以为工人提供新的和更有挑战性的工作。
公司迅速采用了该建议,并在未向工人加以说明的情况下,公布要求工厂工人必须掌握三项以上技能以及每周实施轮岗。该要求发布后,工人表示极大的不满,流言飞语在公司中传播。例如有的工人认为这只是一种管理上的诡计,这给他们增加了负担,却没有任何收益;有的认为这是某个主管为了升职而做出的鬼主意,利用工人的血汗换得个人利益等。一个星期后,工人罢工,装配线关闭。

人事经理试图通过改变工作方式和扩大工作范围来提高工人的兴趣,这种方式属于双因素理论中的( )。

A.保健因素

B.激励因素

C.兴趣因素

D.工作因素