问题 选择题

下列各组物质投入水中,搅拌后能得到无色、澄清溶液的是

A.KNO3、HCl、CuCl2

B.NaOH、Na2CO3、H2SO4

C.MgSO4、NaC1、Ca(OH)2

D.FeCl3、KCl、Na2SO4

答案

答案:B

A、三物质间不会发生反应,但Cu2+在水中为蓝色,不会得到无色溶液,故A错误.

B、氢氧化钠与稀硫酸能够发生反应生成硫酸钠与水,碳酸钠和硫酸也能发生反应生成硫酸钠水与二氧化碳,反应后溶液中离子均是无色的,能得到无色、澄清溶液,故B正确.

C、Ca(OH)2和MgSO4可以发生反应生成氢氧化镁的白色沉淀,不能得到澄清溶液,故C错误.

D、三钟物质间均不反应,但氯化铁是黄棕色溶液,不能得到无色溶液,故D错误.

故选B.

阅读理解

阅读理解

     American culture is unique because it is formed and developed under certain conditions.The major

factors contributing to the making of this flew nation and the forming of a new culture are the hard

environment, ethnic diversity(多民族) and plural religion, which is quite different from other nations in

the world.What is more, these elements are still influencing the American culture.

     The early immigrants who were English Puritans settled down in northeast part of America. From

1607 to 1892, frontiers were pushed further west.The frontiersmen looked for a land of rich resources

and a land of promise, opportunity and freedom.Actually they looked for a better life.So individualism

(个人主义), selfreliance, and equality of opportunity have perhaps been the values most closely

associated with the frontier heritage(遗产) of America.

     In history, people from different countries in the world rushed to America three times.They brought

their own culture to America and later on,different cultures were mixed together.Thus the unique

American culture is formed,a common cultural life with commonly shared values.

     The fundamental American belief in individual freedom and the fight of individuals to practice their

own religion is at the center of religious experience in the United States.The great diversity of ethnic

backgrounds has produced religious pluralism; almost all of the religions of the world are now practiced

in the United States.

     Nowadays, we can see the continual influence of the three elements in the current American society.

American family is typically parents and their unmarried children.Middleaged and elderly people generally do not live with their married children.The people in America have a very strong desire to start a new life

in a new place.Quite a number of people change residences every year.The average American moves

fourteen times in his lifetime.

1. American culture is unique because of the following factors EXCEPT________.

A. hard environment  

B. ethnic diversity

C. plural religion  

D. advanced modernization

2. We can learn from this article that________.

A. the frontiersmen left important society values for American culture

B. the early immigrants brought about the unique American culture

C. people in the world once rushed to America because of its unique culture

D. the American family members don't get along well with each other

3. What's the author's attitude towards American culture?

A. He is critical of it.  

B. He admires it very much.

C. He just states the facts.  

D. He looks down upon it.

4. What might be the most suitable title of this article?

A. The Immigrants in America

B. Why American Culture Is Unique

C. The Influence of American Culture

D. Plural Religion and American Culture

问答题 简答题