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.

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小题1:The Great Green Wall in China is ______. A．7,000 kilometers long B．1,700 kilometers long C．7,000 meters long D．400 kilometers long

小题2:Trees must be grown in ______. A．China B．the USA C．some countries D．every part of the world

小题3:Which of the following statements is not true? A．The Great Green Wall will stop wind from blowing the earth away. B．The Great Green Wall will make our life better. C．We don’t need to plant more trees. D．The Great Green Wall will stop the sand moving towards the rich farmland.