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These big stones leave long tracks(轨迹) behind them. The long tracks show that the stones have moved along the ground. But how do they move? Scientists have tried to answer this question for the last 50 years. These famous moving stones are in Death Valley(死亡谷), the USA. Many of the stones are small but a few of them are very big. Some of the big stones are as big as a man. The biggest stones weigh 350 kilograms. They are heavier than four men! The stones only move at night and only once every year or two. Nobody has ever seen them moving, but now scientists know the answer to the question.
These big tracks show that the stones have moved along the ground. But how do they move? Scientists have tried to answer this question for the last 50 years. These famous moving stones are in The Death valley, the USA. Many of the stones are small but a few of them are very big. Some of the big stones are as big as a man. The biggest stones weigh 350 kilograms. They are heavier than four men. ! The stones only move at night and only once every year or two. Nobody has ever seen them moving, but now scientists know the answer to the question.