问题 选择题

下列物质中,哪种能由金属与稀酸反应直接制得(  )

A.CuSO4

B.FeCl3

C.Al2(SO43

D.AgCl

答案

由于金属铜和银都排在氢的后面,因此都不能和稀酸反应,故A和D错误;

而铁和稀酸反应生成的都是亚铁盐,故B错误;

由于铝在氢前,铝和稀硫酸反应生成硫酸铝,故C正确;

故选C

阅读理解

阅读理解。

     It is possible that in 50 years the only tigers in the world will be in zoos. One

hundred years ago there were  maybe 100,000 tigers in the world. Today scientists are not sure how many are left, as it is difficult to count them. There rnay be only between 5,000 and 7,000 tigers in the world.

      Tigers are only found in Asia. Already they have disappeared from many

countries. There are no longer any Caspian(黑海的) tigers in Central Asia. They have died out in the two  islands  of Java (爪哇 ) and Bali (巴里) . The situation in some

parts of Asia is also very serious. There are perhaps only 100 Chinese tigers left. In

eastern Russia, the number is a little higher. There are about 450 tigers left. On the

island of Sumatra (苏门答腊) , which has many thick forests , there are maybe 500

tigers.

      Why has the number fallen so quickly? The first reason is that tigers are

meat-eaters. They need a lot of land to find enough food. Also they live in forests and many of these have been cut down. At one time, tiger shooting was a sport ,

especially in India. Local(当地的) people some- times kill tigers because they kill their cows. The other reason is that dead tigers are used for Traditional Chinese Medicine. All parts of the body are used, including the bones and whiskers (须) . People who

take TCM think chat these medicines will make them live longer.

      How can we protect the tigers that are left? First, some wildlife parks have been

created. In these reserves (自然保护区 ) ,local people may not kill tigers and the

forests may not be cut down. And 145 countries have agreed to stop selling tiger

parts for medicine. With luck , the tigers can be protected in the few areas of the

world where they still live.             

1. Which part of the world has the most tigers today?

A. Central Asia.          

B. Fastern Russia.

C. Sumatra.              

D. China.

2. Why arc there fewer tigers today?

A. Forests are needed for cows.

B. Tigers don't like living in forests.

C. Tigers have been killed for TCM and to protect other animals.

D. People still kill tigers for sport.

3. The third paragraph tells us that         .

A. only two parts of the tiger's body are used in TCM

B. all parts of the tiger's body are used in TCM

C. people have kept tiger's body parts for a long time

D. scientists know that TCM gives people a longer life 

4. Which of these plans will not protect tigers?

A. Stop local people from killing tigers.

B. Protect cows from tigers.

C. Stop selling tiger's body parts for TCM.

D. Stop cutting down forests.

5. What's the best title for the passage?

A. Killing the tigers

B. Saving the tigers

C. Fewer and fewer tigers left

D. More and more tigers needed

判断题