The world is not only hungry but also thirsty for water. This may seem strange to you, since   (1)  

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   (2)   water from rivers, lakes, underground and so on. And we can not even use all of that   (3)   some of it has been made dirty.

Earth Day is on 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   (4)   the earth. Today we   (5)   serious water problem. One of them is water pollution. All kinds of things from cars, factories, farms and homes make our rivers, lakes and oceans   (6)  . 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 polluted the air. Then when it   (7)  , the rain water makes our drinking water dirty. Dirty rain, called acid rain, is also bad for plants, animals and buildings. Scientists say that in 30 years, more than half of the people in the world   (8)   have enough clean water. We have to learn how to stop   (9)   water. The first step is to develop ways of reusing it.

Even though every large cities   (10)   its water, we would still not have enough water. 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.

It is autumn. A strong wind is blowing. It   (1)     flower seeds（种子）high in the air. One of the seeds is small. Will it be able to keep up    (2)   the others? Finally the wind stops and seeds fall quietly down on the ground.

Now it is   (3)     . After a long trip the seeds feel very   (4)    . They look just as if they are going to sleep in the earth. Snow falls and covers them like a soft white blanket.

Spring comes. It gets warm. The sun shines. Rain falls. The seeds grow   (5)  full and round that they start to break open a little. Now they are not    (6)   . They are plants. First they put roots (根) into the earth. Then their little stems（茎）and leaves begin to dance in the sun and air.  

In summer, the small plant is all alone. It grows on and doesn’t stop. The sun shines on it   (7)    the rain waters it. It has many leaves. It grows taller and taller. It is   (8)    the people. It is taller than the trees. And now some flowers grow on it.

Autumn comes back. The wind blows past the flowers .    (9)   petals (花瓣) drop over the land and down to the ground. The wind blows harder. The flowers have lost all of their petals. Once more the wind shakes the flowers, and this time the flowers’ seed pods (荚) open. Many new seeds come out. Quickly in the wind they are    (10)    to new plants again. 

     Today we can see that many people are cutting down the trees in the forests. A lot of rich land has become   41 . If we read newspapers, we’ll learn that the forests on the earth are getting smaller   42 . We are cutting down large number of trees   43  we need wood. Some scientists say that there will not be any great forests   44  20 or 30 years.

         What will happen if the forests disappear? A lot of plants will die and the animals will   45  their homes. In many places the new farmland will soon   46  the old desert. Crops will not grow there. There won’t be enough   47 , and the weather will get hot and dry. If the climate of the earth changes, life will be   48  for everyone. Our living environment will become worse and worse. More and more rich farmland will disappear. We will suffer a lot of from both droughts (干旱) and floods.

       So it’s our duty   49  the forests well. Everyone should try his best to make a contribution (贡献) to taking care of the forests. Stop   50     down the trees and make the world greener.

The world   (1)   many interesting sounds. Some are unpleasant to our ears while   (2)   are very pleasant to hear. In a single day you probably hear   (3)   sounds. All sounds are different. Some   (4)   loud, some sounds are high, others are low, some sounds are useful.

  (5)   sounds we can’t talk or listen to each other. The ringing of the alarm clock wakes people up. The hooting(鸣笛声) of a car warns people of danger.

Some sounds are harmful. When planes fly low   (6)   the land, the very loud sounds can damage(毁坏) the houses. Very loud sounds can even make people deaf.

We know sound travels about one kilometer in three   (7)   In a thunder storm(雷雨) you see the lighting(闪电) first and then hear the thunder. This is because light travels   (8)   than sound.

Next time you see lighting, count the number of seconds before you hear the thunder. Divide(除以) this number   (9)    This will tell you   (10)   kilometers away the thunder storm is.

Football is a popular sport. There are many games in different places every year.  (1)  good players want to take part in the World Cup. It is held every four  (2)  . Only the best team can  (3)  the last game.

The 2014 World Cup was held in Brazil. Hundreds of thousands of people went to the games or   (4)  them on TV day and night. They all got very  (5)  .

Football is a  (6)  sport. There are eleven  (7)  in each team of a game. The earliest（最早的）games of football in England were different  (8)  today. The people in two towns（城镇） played the game. Each team of the town  (9)  over five hundred players, and each team had to try to carry the ball to  (10)  team’s town. Today some towns in England still play games like this.

It is said that eyes can speak. Do you have such kind of 36 ? In a bus you may look at a stranger, but not too 37 . If he notices that he is being looked at, he may  38  uncomfortable. It is the same in daily life.

When you are looked at for several more times, you will look 39 up and down in order to 40 if there is anything wrong with you. If 41 goes wrong, you will feel angry with the person who is looking at you, 42 can speak, right?

Looking too long at someone may seem to be impolite. But sometimes things are 43 . If you wish to draw someone’s 44 , you may look at him or her more than ten seconds. For lovers, they enjoy looking each other longer to show the love that words cannot  45  .

Clearly, eye communication should be done according to the relationship between the two people and the certain situation.

How much do you learn about the solar system? The following passage will tell you.

The earth is a planet. It as well as seven   (1)   planets goes around the sun. We   (2)   the eight planets and the sun the solar system. The first planet,   (3)   the sun, is Mercury(水星). It is 58 million   (4)   from the sun. Venus(金星) is the second planet next to the sun, and   (5)   planet, the earth, is the third. It is 150 million kilometers from the sun.

Jupiter(木星), Saturn(土星), Neptune(海王星) and Uranus(天王星) are all       (6)   than the earth,   (7)   Venus, Mars and Mercury are smaller than the earth.

    Animals, trees and humans can only   (8)    on the earth—the other planets in our solar system do not   (9)    air or water. Do any planets in other galaxies have   (10)  ? We don't know about it.

We always check the weather before a trip. But after hearing a lot about air pollution, we often wonder:   (1)   will the air be tomorrow?

  (2)   September 1st, forecasting air pollution (预报空气污染) started to be on TV. There are six grades(等级), with the first grade  (3)  excellent air.

The forecast helps us   (4)   trips, and helps the government make plans to stop air pollution. China is trying its best to   (5)  the air. Big cities such as Beijing and Shanghai are taking the air pollution  (6)   first. On September 2nd, Beijing said it would   (7)   PM2.5 density (密度) by at least 25 percent by 2017.

How will the city make it  (8)  ? Car emissions (排放物) is one of the main   (9)  of PM 2.5 in big cities. So fewer cars will be in Beijing next year. It is also  (10)   congestion fees (拥堵费) from cars driving in the city center. There’s a lot of PM 2.5 in waste gas from   (11)  . Beijing will close some. If a factory pollutes heavily, it will have to buy water and electricity (电) at a   (12)   price. In order to have more blue  (13)   , each of us should also help.

We can help by  (14)  buses instead of cars or taxis. We can  (15)  help by giving up smoking and eating by the street!

So from now on, take action and do your part.

The World Wide Web was invented（发明）by a British scientist named Tim Berners-Lee in 1989. He wanted to send documents(文件)to 51         scientists. So he developed the World Wide Web. This allowed him to 52         and get scientific documents with text, drawings and photos (also called multimedia documents). From 1990, more and more people___53____ to use the Internet and the World Wide Web.

So what’s the difference   54the Internet and the World Wide Web? The Internet is the hardware（硬件）. It allows us to communicate 55         other people. The World Wide Web is the software. It allows us to create, see, and read multimedia documents.

The web is made up of ___56_____ documents called web pages. These pages are held in computers all over the world. Many people have a favorite website with a number of web pages on

57          same subject.

Email is a way of   58          your computer to send and get messages, It’s cheaper and quicker to use email 59        send normal mail. New users call normal mail “snail（蜗牛）mail” because it’s so slow!

It took 50 years for 100 million people __60____ to radio. It took 15 years for 100 million people to watch TV. By the year 2000, it had taken only about three years for 100 million people to use the Internet. What will happen next on the Internet?

We know that trees are useful in our everyday life. They  (1)   us many things, such as wood, oxygen (氧气), rubber(橡胶), medicines and many other things. They can    (2)  tell us a lot abou t our climate. The following are the reasons(原因). If you cut down a tree, you can see that it has many rings (年轮). Most trees grow one new ring every year. Because of this reason, we know  (3)   a tree is. A tree over a hundred years old means that it has more than a hundred rings When the climate is dry or very cold, the trees do not grow very much and their rings are usually   (4)   . When it is wet and warm, the rings are much thicker. If the rings are suddenly very thin or suddenly very thick, this means that the  climate changed suddenly(突然). If we look at the rings of this tree, we can   (5)   about the climate for a hundred years. We can see  how our climate is changing today.