问题 问答题 简答题

计算题:某企业甲产品投产后预计收益情况和市场情况有关,可用下表描述各种可能的收益概率分布。

答案

参考答案:

(1)期望值E=5×0、1+4×0、2+3×0、4+2×0、2+1×0、1=3 

(2)标准离差=1.095 

(3)标准离差率=1.095÷3=0.365

填空题

(16分)“家”是一个化学小世界,蕴含丰富的化学知识。

(1)分析下列与食品有关的物质,回答问题:

① 碳酸饮料中常加入防腐剂——苯甲酸(C6H5COOH)。该防腐剂属于        (填“有机物”或“无机物”)。

② 常用的食品干燥剂——生石灰(如下图),其干燥吸水的原理是                                (用化学方程式表示)。分析图中“不可食用”的原因是              (写一点)。

③ 常用的食品脱氧剂——还原性铁粉,其脱氧原理是:

常温下铁与           和          共同作用而生锈。

(2)表1为几种家用清洁剂的功能及有效成分:

名 称洁厕灵活氧彩漂漂白精
功 能有效清除污垢与异味漂洗使衣物色彩鲜艳快速漂除衣物污渍
有效成分HClH2O2NaClO
表1

①不宜用“洁厕灵”清洗大理石地面的原因是                   (用化学方程式表示)。欲测定“洁厕灵”的酸碱度,可选用      (填标号)。 

A.pH试纸    B.酚酞溶液 C.石蕊溶液

② 往“活氧彩漂”液体中加入少量二氧化锰,观察到的现象是__________________, 

反应的化学方程式为                                                 

③“洁厕灵”与“漂白精”不能混用,二者混合易产生一种有毒气体X。反应

原理为:NaClO + 2HCl =" NaCl" + X↑ + H2O ,则X的化学式为          

阅读理解

Certain people make you feel comfortable when they are around. You spend an hour with them and feel as if you’ve known them half your life. These people have something in common. And once you know what it is, we can try to do it ourselves.

How is it done? Here are several skills that good talkers have. If you follow the skills, they will help you to put people at their ease, and make friends with them quickly.

First of all, good talkers have asked questions. Almost anyone, no matter how shy he is, will answer a question. One well-known businesswoman says, “At business lunches, I always ask people what they did that morning. It’s a common question, but it will get things going.” From there you can move on to other matters ----sometimes to really personal questions. And how he answers will let you know how far you can go.

Second, once good talkers have asked questions, they listen for the answers. This point seems clear, but it isn’t. Your question should have a point and help to tell what sort of person you are talking to. And to find out, you really have to listen carefully and attentively.

Real listening at least means some things. First it means not to change the subject of conversation. If someone sticks to one topic, you can take it as a fact that he is really interested in it. Real listening also means not just listening to words, but to the tone (语调)of voice. If the voice sounds dull, then it’s time for you to change the subject.

Finally, good talkers know well how to deal with the occasion of parting. If you’re saying goodbye, you may give him a firm shakehand and say, “I’ve really enjoyed meeting you.” If you want to see that person again, don’t keep it a secret. Let people know what you feel, and they may walk away feeling as if they’ve known you half their lives.

小题1:You’ll like to stay with some people____.

A.who have something in common with you

B.when you get into real trouble

C.with whom you feel it easy to get along well

D.from whom you can get necessary and timely help小题2:After asking somebody a question, you should____.

A.make it clear what is fit to ask next

B.wait quietly for his answers

C.go on to ask more questions

D.change the subject to another one小题3:If you want to see that person again,____ when parting.

A.let him know what you feel

B.giving them a firm shakehand

C.asking proper questions and being a good listener

D.keeping talking to others to them in the conversation