Passage One 

Scientists are trying to make the deserts into good land again. They want to bring water into desserts so that people can live and grow food. Even so,more and more of the earth is becoming desert all the time. 

Why? Scientists think that people make deserts. People are doing bad things to the earth. 

Some places on the earth do not get very much rain.Yet,they still do not become deserts.This is because there are some small green plants growing there.Plants help keep water in the earth.Plants do not let the wind blow the dirt away.Without plants,the land can become a desert much more easily. 

A man decides to make a farm in a very dry place.He digs in the earth and takes away the grass and plants that are already growing on the dry land. 

He makes a farm.He puts plants in rows.The sun is very hot.It makes the land even drier.When the rain comes,it runs between the rows of plants.It washes the good dirt away.When the wind comes, it blows between the rows of the plants.It blows the good dirt away.Soon the land is not good enough for a farm any more.The man lets his animals eat all the plants on it.Now the land does not have any plants on it.The sun and wind dry the land and all of the good dirt away.Now the land is a desert. 

A desert is probably______. 

.Land is becoming desert because of lack of______. 

Which of the following is NOT the reason why small green plants are very important to dry places? 

It can be inferred from the passage that______ . 

What’s the purpose of the writer to give an example of the man?______.