问题 选择题

不用外加试剂把下列溶液鉴别出来的先后顺序正确的是:(  )

①CuCl2 ②NaNO3 ③MgCl2 ④NaOH.

A.①②③④

B.①③④②

C.④①②③

D.①④③②

答案

由于氯化铜溶液呈蓝色,因此可以用观察的方法首先确定出氯化铜溶液.

由于氯化铜溶液与氢氧化钠溶液能生成蓝色沉淀氢氧化铜,因此可以将其它溶液取少量与试管中,分别滴入几滴氯化铜溶液,能产生蓝色沉淀的就是氢氧化钠溶液.

由于氢氧化钠溶液与氯化镁溶液能生成白色沉淀氢氧化镁,而与硝酸钠溶液不反应,接触时没有现象产生,因此可以将其它两种溶液各取少量于试管中,分别滴入几滴氢氧化钠溶液,有白色沉淀生成的是氯化镁溶液,没有沉淀生成的是硝酸钠溶液.

因此鉴别出各物质的顺序是①④③②.

故选D.

阅读理解

When you finish high school or university, is learning done? The answer is “no”. In many countries, people continue learning all their lives. Why is lifelong learning important? How can it help you? Let’s look at one example of lifelong learning in Japan.

Why is lifelong learning important?

You go to school and learn. You take tests. But learning doesn’t only happen in school. And learning doesn’t stop when you graduate from high school or college. You are learning all the time. For example, learning can happen when you go to a museum. It can also happen when you get a job. You learn when you play a sport or when you take a trip. Learning is life! We never stop learning. Every day, you can improve yourself by learning something new.

Lifelong learning in Japan

In Japan, life learning is very important. People in Japan like to try new learning activities. Music calligraphy, flower arranging, and foreign languages are some of their favorite classes. The Japanese take classes to improve their skills and learn new things.

Conclusion

When we graduate from school, we can continue to learn. Make lifelong learning one of your goals!

小题1:Why is lifelong learning important?

A.It helps you improve yourself.

B.It’s the best way to learn.

C.It’s fun and easy.

D.It’s an important goal.小题2: Some people in Japan take foreign language classes to       .

A.get a job

B.learn new things

C.get good grades

D.finish college小题3:Which of the following is TRUE according to the passage?

A.Learning only happens in school.

B.When we graduate from school, learning is done.

C.You can’t learn anything when you play a sport.

D.Music, calligraphy, flower arranging and foreign languages are popular classes in Japan.小题4:What is the main idea of the reading?

A.Learning can be fun.

B.We are always learning in school.

C.Finishing high school is important.

D.People can learn all their lives.

问答题 简答题