The students were having their chemistry(化學(xué))class. Miss Li was telling the children what water was like. After that, she asked her students, “What's water?”No one spoke for a few minutes.Miss Li asked again，“Why don't you answer my question?Didn't I tell you what water is like?”

　　Just then a boy put up his hand and said，“Miss Li，you told us that water has no colour and no smell.But where to find such kind of water?The water in the river behind my house is always black and it has a bad smell.”Most of the children agreed With him.

　　“I'm sorry，children.”said the teacher，“Our water is getting dirtier and dirtier.That's a problem.

　　1.The students were having their _______ class.

　　A.English B.Chinese C.chemistry D.maths

　　2.Miss Li was telling the children what ______ was like.

　　A.water B.air C.earth D.weather

　　3.A boy said，“The water in the river behind my house is always _______.”

　　A.white B.black C.clean D.clear

　　4.Most of the children _______ the boy.

　　A.agreed with B.wrote to

　　C.heard from D.sent for

　　5.The water in the river has colour and smell because it is getting _______.

　　A.more and more B.less and less

　　C.cleaner and cleaner D.dirtier and dirtier

　　KEY: 1.C 2.A 3.B 4.A 5.D

　　In 1620, about half the USA was covered by forests. Today the forests have almost gone. A lot of good land has gone with them, leaving only sand. China doesn't want to copy the USA's example. We're planting more and more trees. We've built the " Great Green Wall" of trees across northern part of our country.The Great Green Wall is 7,000 kilometres long, and between 400 and 1,700 kilometres wide. It will stop the wind from blowing the earth away. It will stop the sand from moving towards the rich farmland in the south. More "Great Green Walls" are needed. Trees must be grown all over the world. Great Green Walls will make the world better.

　　根據(jù)短文內(nèi)容，選擇正確答案。

　　1.In 1620, about ______ the USA was covered by forests.

　　A.a third B.half C.two thirds D.a fourth

　　2.A lot of good land has gone with ______.

　　A.sand B.water C.wind D.forests

　　3.The Great Green Wall in China is ______ long.

　　A.7,000 kilometers B.1,700 kilometers

　　C.7,000 meters D.400 kilometers

　　4.Trees must be grown in ______.

　　A.China B.the USA

　　C.some countries D.every part of the world

　　5.______ will make the world better.

　　A.The Great Wall B.Tall buildings

　　C.Great Green Walls D.Flowers and grass

　　KEY: 1.B 2.D 3.A 4.D 5.C