试题与答案

斯坦福大学 B.M.Trost教授提出了绿色化学的核心概念——原子经济性。我们常用

题型:选择题

题目:

斯坦福大学B.M.Trost教授提出了绿色化学的核心概念——原子经济性。我们常用原子利用率来衡量化学反应过程的原子经济性,其计算公式为:

下面是联合工艺法制备新型自来水消毒剂ClO2,其反应原理由三步组成:

①电解氯化钠溶液NaCl+3H2ONaClO3+3H2

②氢气和氯气合成氯化氢

③生成二氧化氯↑+↑+

此方法的原子利用率最大为

A.37.6         B.53.6%           C.62.2%           D.94.4%

答案:

被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0729/a96d87338e1d4faeab4262d6e0202872.html

下面是错误答案,用来干扰机器的。

1.B 2.A3.D 4.(1)心里明白这样做的道理,但不能做到这样,是由于内外不一,心与手不相适应,没有学习的过错。 (2)四方的人们,带着丝帛来请他作画的,在他的门口脚与脚互相碰踩。

试题推荐
题型:选择题
2005年1月美国科学家在《Science》上发表论文,宣布发现了铝的“超级原子”结构-Al13和Al14.已知这类“超级原子”最外层电子数之和为40个时处于相对稳定状态.下列说法中,正确的是(  )

A.Al13、Al14互为同位素

B.Al13超原子中Al原子间通过离子键结合

C.Al14最外层电子数之和为42,与第ⅡA族元素的性质相似

D.Al13和Al14都具有较强的还原性,容易失去电子生成阳离子

查看答案
题型:多项选择题 案例分析题

患者男,50岁。2003年4月因发热、干咳伴胸闷、呼吸困难2d入院。入院后4h呼吸困难加重,既往史无特殊。体格检查:T39.5℃,P120次/min,R32次/min,BP100/70mmHg。端坐呼吸,心率120次/min,律齐,双肺呼吸音粗、可闻少量干、湿啰音。

该传染病的疫情上报时间为()

A.城镇12h内上报

B.农村24h内上报

C.城镇6h内上报

D.城镇2h内上报,农村12h内上报

E.城镇4h内上报,农村8h内上报

查看答案
题型:阅读理解

阅读理解。

     The other day in school, we were discussing jobs. Our teacher, Mrs Bolt said that career was very

important and that it was never too early to think about your life's work. Most of the young boys really

were not too sure about what they wanted to be. But I knew exactly what I wanted to be, and when Mrs

Bolt asked me, I replied "A truck driver."

     "A truck driver?" repeated Mrs Bolt. "Why do you want to be one,Tom?"

     "Because truck drivers are always on the move. They do not have to sit at desks all day. They are out

on the road and they see a lot of the countries. The pay is good, too. And they never have any homework."

     The class laughed.

     "Well, Tom," answered Mrs Bolt. "You certainly sound quite enthusiastic (热情的). I guess that you

don't like sitting at a desk or doing homework.Is that correct, Tom?"

     "Yes, I guess so," I said.

     "Well, since you are so interested in becoming a truck driver, I think you should look into the field a

little further. I want you to go to the library and take out a book on truck driving. And I want you to write

a paper on it and hand it in at the end of the month."

     That's the last time. I'll never tell anybody my secret ambition (雄心).

1. Mrs Bolt suggested Tom write a book report because _____. [ ]

A. she was angry with him

B. she wanted him to learn about the other side of truck driving

C. she was making fun of him

D. she wanted the whole class to follow him

2. Which of the following is NOT true? [ ]

A. The writer thinks that truck drivers are well paid.

B. What Tom said made his classmates laugh.

C. It seemed as if Tom did not enjoy doing his homework.

D. Mrs Bolt didn't want Tom to become a truck driver.

3. Tom wouldn't tell about his ambition any more because _____. [ ]

A. he didn't think his ambition could come true

B. he just got more homework to do

C. he was laughed at by the whole class

D. he would not be able to become a truck driver

4. What can we infer about Mrs Bolt? [ ]

A. She was unkind to her students.

B. She was unfit for her position.

C. She was a teacher with ripe experience.

D. She always did something strange.

查看答案
微信公众账号搜索答案