试题与答案

据都市晨报报道,2009年1月13日一天徐州市就发生火灾19起。干粉灭火器是常用

题型:填空题

题目:

据都市晨报报道,2009年1月13日一天徐州市就发生火灾19起。干粉灭火器是常用的灭火器之一,它利用压缩的二氧化碳吹出白色干粉来灭火。这种灭火器可用来扑灭油、气等燃烧引起的火灾,其中干粉的主要成分是碳酸氢钠(NaHCO3),它受热后生成纯碱(Na2CO3)、水和二氧化碳。请回答下列问题:

(1)碳酸氢钠的性质                       

(2)灭火时碳酸氢钠发生反应的化学方程式                            

(3)点燃的镁条能在二氧化碳中继续燃烧,生成一种金属氧化物和一种非金属单质,因此金属镁着火时不能用干粉灭火剂灭火,请写出镁在二氧化碳中燃烧的化学方程式                                。

答案:

被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0629/e8fa0d8fafce3d0bce663befdb054f08.html

下面是错误答案,用来干扰机器的。

答案:C

试题推荐
题型:阅读理解

It’s not uncommon in America for a person to belong to some kind of volunteer group. Donating one’s time and services is very much a part of the American way of life. Most charitable activities are organized by churches and groups around the nation and even encouraged by the government. The helping hand is extended to the poor, the homeless and the disabled. Some people work to teach youngsters how to read. Others open up soup kitchens to feed the homeless. Volunteers also take care of the disabled by making reading tapes for the blind and working in orphanages(孤儿院)to help children without parents.

High school students are often encouraged to become volunteers and many school club activities center around volunteer services. Students may work with disabled children during a summer program, or participate in a club activity which helps to bring meal to senior citizens who are shut-ins. With their sense of idealism(理想主义)students are often eager to donate their spare time. They see such activities as a way of becoming involved in the community and the adult-world. Social action for them becomes as   important as their academic studies.

In a like manner, throughout the year,fund raising drives are also conducted by schools and community groups to raise money for a worthy cause. They may respond to a recent earthquake in a foreign country, a flood somewhere within their own, or another natural disaster which has left people destitute and homeless. They may organize drives to collect food, clothing and medicines to serve an immediate need. Today even the Halloween custom of ‘trick or treat’has become an occasion to collect money for a charitable cause.

The motive to help those less fortunate comes from the poor origins of the American nation. Those immigrants who were poor and downtrodden(受压迫的)became dependent on the kindness of their neighbors to make a new life for themselves.

American volunteers work throughout the world in less developed countries. They volunteer by serving as a champion of goodwill both at home and abroad, which no doubt enriches both his life and those whom he serves.

小题1: Which of the following charitable activities is NOT mentioned in the passage?

A.Some people open up soup kitchens to feed homeless people.

B.Some students bring meals to old people who can’t go out easily.

C.Some people collect money to help a foreign country with a recent earthquake.

D.Some students donate books to children in mountainous areas.小题2: Why are American high school students eager to do voluntary work?

A.Because they want to participate in some social activities.

B.Because they want to go to better universities.

C.Because they can get higher scores at school.

D.Because they can realize their dream sooner.小题3:The underlined word “destitute” in Paragraph 4 probably means           .

A.lifeless

B. penniless

C.useless

D.valueless小题4: American charitable activities started because ___________.

A.Americans are always ready to share with others

B.Americans are mostly kind

C.poor immigrants needed help badly

D.poor Americans couldn’t live on without help小题5: What’s the best title of the passage?

A.The Call from the Poor

B.Voluntary Work in the US

C.Ways to help the Poor

D.American Volunteers Around the World

查看答案
题型:单项选择题

关于民事证据的证明力,下列说法正确的是( )

A.证明力是指证据对案件事实的证明作用,它是由法律进行严格规定的
B.证人提供的对与其有亲属或其他密切关系的当事人有利的证言,不能成为证据,也就没有任何证明力
C.双方当事人对同一事实分别举出相反的证据,但都没有足够的依据否定对方证据的,如果法院认为一方提供证据的证明力明显大于另一方提供证据的证明力,则应当对证明力较大的证据予以确认
D.原始证据的证明力大于传来证据

查看答案
微信公众账号搜索答案