The world is not only hungry but also thirsty for water. This may seem strange to you, since nearly 70%of the earth's surface is covered with water. But about 97%of that is sea water or salt water. Man can only drink and use the other 3%of fresh water from rivers, lakes, underground and so on. And we can not even use all of that because some of it has been made dirty.

    Earth Day is April 22. But on all other days, we must also remember how important water is. The water that we use is the most important natural resource on the earth. Today we face serious water problems. One of them is water pollution. All kinds of things from cars, factories, farms and homes make our rivers, lakes and oceans dirty. Polluted water is very bad for people to drink. And dirty water is bad for fish, too.

    How do cars and factories make our water dirty? First they pollute the air. Then when it rains, the rain water makes our drinking water dirty. Dirty rain, called acid rain（酸雨）, is also bad for plants, animals and buildings. Scientists say that in 30 years, more than half of the people in the world won't have enough dean water. We have to learn how to stop wasting water. One of the first steps is to develop ways of reusing it. Today in most large cities, water i~ used only once and then sere out into a sewer system（下水道）. From there it returns to the sea or goes underground.

    But even though every large city reused its water, we would still not have enough. So we should make use of sea water by removing the salt in it. If we can take these steps, fresh water won't be used up.

1. The world is thirsty for water because______.

 A．we don't have enough fresh water

 B．a lot of water goes into sewer systems

 C．only 70% of the earth's surface is water

 D．sea water is widely used rather than fresh water

2. The underlined word "face" means"______".

 A．turn the face down                      B．turn the face up

 C．turn the face to                            D．turn the face back

3. From this passage, we know acid rain________.

 A．is only bad for living things

 B．is not bad for buildings and factories

 C．can be produced in factories

 D．is bad for people, animals, plants and buildings

4. One difficult way we can solve the problem is to ______.

 A．use the water with salt in it                           B．remove the salt from sea water

 C．get water from underground                         D．reuse the water in cities

5. What is the best title for this passage?

A．Fresh water and sea water                           B．A thirsty country

C．The importance of water                            D．The world's water problem

When you’re curious （好奇） about something, and want to know more about it, you can use the way of asking questions. Asking questions is the first step to make discoveries and find interesting answers. The steps below can guide you during the research （研究）.

Step 1   On a notecard or piece of paper, write down the subject that you are interested in. Just get the main idea down. For example, you might write: Discover more about dinosaurs.

Step 2   Next, stop and think for a moment about what you already know about your subject. List what you already know like the sentences below:

（1） Dinosaurs lived long before human beings appeared.

（2） Dinosaurs lived on the earth for more than 150 million years.

（3） Some dinosaurs fed on plants, some on meat.

Step 3   What can you do with what you want to learn? By asking questions. On your paper, start writing down questions about the dinosaurs as you think of them:

（1）What’s the best weather for dinosaurs to live in?

（2）How many kinds of dinosaurs are there?

（3）Have dinosaurs really disappeared?

Step 4   Armed with your list of questions, you can now go to the nearest library or computer to begin your research. As you learn more about your subject, you’ll probably discover some new questions. For example, you might discover that dinosaurs disappeared about 65 million years ago. Why? What happened? Asking new questions can help you research your subject more widely.

The next time you find something interesting to research, take time to organize （组织） your thinking by asking good questions. And remember — learning more always brings more questions.

1．When you do some research, you should take the following steps:        .

  ① list what you want to know          ② choose a research subject

③ list what you already know          ④ discover new problems

A．④③①②       B．①④③②       C．②③①④        D．③②④①

2．From the passage, we know  .

A．dinosaurs appeared after human beings

B．not all the dinosaurs fed on meat

C．dinosaurs lived on the earth for 65 million years

D．dinosaurs liked warm seasons

3．What does “Armed with your list of questions” mean?

A．Putting your list of questions under your arm

B．Discussing your questions with your classmates

C．Writing down your list of questions

D．Taking your list of questions with you

4．According to the passage, which one is true?

A．You can find all the answers online

B．Learn more, and you’ll have no questions

C．Asking questions is the only way for research

D．During the research, you may keep finding new questions

5．The best title for this passage is “                        ”.

A．Discovering Dinosaurs                 B．Asking Good Questions

C．Finding Subjects                      D．Learning Steps

In most situations, light helps us see．But nowadays humans are using too much of it so that it is in fact a kind of pollution．

When it comes to looking at the night sky, too much light makes it difficult for us to watch some of life’s most wonderful sights: stars, planets and even galaxies（星系）．

According to scientific research, about 2, 500 stars can be seen by the human eye without using any special equipment（设备）．But because of light pollution, you can only see 200 to 300 stars from today’s countryside, and no more than ten stars from a city．In most big cities, people cannot see the sky filled with stars like they did in their childhood．

Light pollution affects more than just our view of sky．Research shows that lots of nighttime light can harm wildlife, too．

When birds fly to another place over cities, they sometimes get lost by the brightness and fly in circles（圈） until they drop from tiredness．Sea turtles（海龟） need dark beaches for laying eggs, but they can’t find their ideal places because of those bright lights．

Too much light at night may even affect human health, but scientists are not sure of that． They are still learning more．

In order to prevent things from going worse, governments and some organizations are working to reduce light pollution．Many cities and towns have taken action to reduce the use of lights at night．Lights are used only when and where they are truly needed．They also shine lights down at the ground instead of up into the sky and use lower brightness levels．

Hopefully, in the near future, humans can enjoy the clear and beautiful sky again and all the wildlife will live a peaceful and undisturbed life, too．

1．Why does the writer think that too much light is a kind of pollution?

A． Because there are fewer and fewer stars．

B． Because human health has been affected．

C． Because too much light is a waste of energy．

D． Because some of the wildlife can be harmed．

2．Which of the following is NOT mentioned（提到）in this passage?

A． The problems that light pollution has caused．

B． The reason why humans use too much light．

C． The ways that light pollution can be reduced．

D． The reason why fewer stars can be seen than before．

3．Which of the following is true according to the passage?

A． There are about 2,500 stars in the sky．

B． Humans want to do nothing to reduce light pollution．

C． Sea turtles always get lost and die from tiredness．

D． Something has been done to reduce light pollution．

阅读下面短文，然后根据要求答题：

Scientists are trying to turn deserts into good land again They want to bring water to the deserts. So people can  live and (A)         food there .However, more and more land is becoming desert, Why? Scientists thank that people are doing bad thing to turn good land into desert.(B)地球上的一些地方雨量不足够，but they do not become desert, This is because green plants are growing there, Some green plants and grass are very important to dry places , Plants do not let the hot sun make the earth even drier, (C)Plants do not let the wind blow the soil away ,When rain falls, plants hold the water .( D )Without plants, land can become desert much  more easily.

1.在(A)的空白处填入一个适当的词语：    

2将划线部分(B)译成英语：                                             

3将划线部分(C)译成汉语：                                              

4将划线部分(D)改写成：

Land can become desert much more easily________there are            plants