1 . Rainforests are home to a rich variety of medicinal plants, food, birds and animals. Can you believe that a single bush（灌木丛）in the Amazon may have more species of ants than the whole of Britain! About 480 varieties of trees may be found in just one hectare of rainforest.

Rainforests are the lungs of the planet-storing vast quantities of carbon dioxide and producing a significant amount of the world's oxygen. Rainforests have their own perfect system for ensuring their own survival; the tall trees make a canopy（树冠层）of branches and leaves which protect themselves, smaller plants, and the forest animals from heavy rain, intense dry heat from the sun and strong winds.

Amazingly, the trees grow in such a way that their leaves and branches, although close together, never actually touch those of another tree. Scientists think this is the plants' way to prevent the spread of any tree diseases and make life more difficult for leaf-eating insects like caterpillars. To survive in the forest, animals must climb, jump or fly across the gaps. The ground floor of the forest is not all tangled leaves and bushes, like in films, but is actually fairly clear. It is where dead leaves turn into food for the trees and other forest life.

They are not called rainforests for nothing! Rainforests can generate 75%of their own rain. At least 80 inches of rain a year is normal-and in some areas there may be as much as 430 inches of rain annually. This is real rain-your umbrella may protect you in a shower, but it won't keep you dry if there is a full rainstorm. In just two hours, streams can rise ten to twenty feet. The humidity（湿气）of large rainforests contributes to the formation of rainclouds that may travel to other countries in need of rain.

1. What can we learn about rainforests from the first paragraph?

A．They produce oxygen.	B．They cover a vast area.
C．They are well managed.	D．They are rich in wildlife.

2. Which of the following contributes most to the survival of rainforests?

A．Heavy rains	B．Big trees.
C．Small plants.	D．Forest animals.

3. Why do the leaves and branches of different trees avoid touching each other?

A．For more sunlight.	B．For more growing space.
C．For self-protection.	D．For the detection of insects.

4. What can be a suitable title for the text?

A．Life-Giving Rainforests	B．The Law of the Jungle
C．Animals in the Amazon	D．Weather in Rainforests

2 . The Great Wall of China winds across the country like a giant stone snake. It is 1,500 miles long, the Wall crosses mountains and rivers. It reaches from the ocean on the east to the desert on the west. The Chinese began their Wall more than 2,000 years ago. They worked on it for hundreds of years. The Chinese wanted to keep out their enemies. At the bottom, the Wall is 25 feet wide. At the top it is about 15 feet wide. The sides of the wall are made of stone and brick, while the inside is filled with earth. Parts of the Wall rise as high as three-storey buildings. Every 100 yards along the Great Wall there is a watchtower where soldiers used to stand to watch for enemies approaching(到来). The road on top of the Wall is wide enough for two wagons(马车) to pass. If we were to build such a Wall now, we would use modern machines. But the Chinese had to build the Wall all by hand. If the Wall were in our country, it would reach from the state of New York to Nebraska. The Great Wall of China is the longest wall ever built.

1. The passage does not say so, but it makes you think that the Great Wall _____.

A．has a gate every 100 yards	B．is used as a road today
C．is still as useful today as it was	D．is as high as three-storey buildings

2. What is meant by the sentence " The Great Wall of China winds across the country like a giant stone snake. " ?

A．It stops the wind from blowing.	B．It can move.
C．It looks like a snake.	D．It is very long.

3. Which of these sentences do you think is right?

A．The Great Wall China was built with modern machinery.

B．The Great Wall goes from New York to Nebraska.

C．There are many snakes inside the Great Wall.

D．The writer of the passage is an American.