问题 问答题

写出下列反应的化学方程式

(1)铁丝在氧气中燃烧______

(2)三氧化硫与氢氧化钠反应______

(3)碳酸氢钠和盐酸反应______

(4)焦炭和氧化铜在高温条件下反应______.

答案

(1)铁丝在氧气中燃烧生成四氧化三铁,反应的化学方程式为:3Fe+2O2

 点燃 
.
 
Fe3O4

(2)三氧化硫与氢氧化钠反应生成硫酸钠和水,反应的化学方程式为:2NaOH+SO3═Na2SO4+H2O.

(3)碳酸氢钠和盐酸反应生成氯化钠、水和二氧化碳,反应的化学方程式为:NaHCO3+HCl═NaCl+H2O+CO2↑.

(4)焦炭和氧化铜在高温条件下反应生成铜和二氧化碳,反应的化学方程式为:2CuO+C

 高温 
.
 
2Cu+CO2↑.

故答案为:(1)3Fe+2O2

 点燃 
.
 
Fe3O4;(2)2NaOH+SO3═Na2SO4+H2O;(3)NaHCO3+HCl═NaCl+H2O+CO2↑;(4)2CuO+C
 高温 
.
 
2Cu+CO2↑.

阅读理解

In Europe, many people make friends between their countries through town twinning. Town or city twinning means two towns in different countries agree and decide to become “twins” with a sister-city relationship.

The people find pen friends in the twin town. They exchange newspapers and stamps. The school teachers discuss teaching methods with the teachers in the twin town. Officials visit the twin town for celebrations. Ordinary people travel to the twin town, too, but not very often if it is far away.

Sometimes, schools even exchange their classes for two or three weeks! For example, German middle school students study for a while at the school in their twin town in Britain, staying with British families. A few months later, their British friends come to study in Germany.

Many British towns are so pleased with the results of the twinning that they set out to find more than one twin town!

Tonbridge, a small town in Kent, for example, has twin towns in both Germany and France. Richmond near London has relationships with Germany, France and even a town in a Balkan(巴尔干半岛的) country!

Town twinning can help make friends. It helps students improve their language skill, and also helps people to understand the differences between nations.

小题1:Which is the best title for the passage?

A.Town Twinning

B.Friendly Towns

C.Exchanging Teachers and Students

D.Peace and Understanding小题2:Which of the following is NOT mentioned in the passage?

A.Twin towns exchange newspapers and stamps.

B.Twin towns exchange business skill.

C.Schools in twin towns exchange classes for a period of time.

D.Ordinary people travel to the twin town.小题3:Twin towns develop ____________.

A.between European countries and China

B.in the English-speaking countries only

C.in the same country

D.between different countries小题4:How many countries are mentioned in this passage?

A.7

B.6.

C.5

D.4小题5:One of the advantages of town twinning is to ________.

A.earn more money

B.set up schools

C.improve students’ language skills

D.develop industry and agriculture

单项选择题