阅读理解。 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.