任务型阅读。（每小题2分，共6分）
阅读下文并回答问题。
People do not usually like floods but some farmers need floods when their fields are too dry.When there is a flood, the water carries mud and sand from the river bed to the field near the river. When the water goes away, the mud and sand become good soil.
People in many countries tell stories about a very big flood. The flood covered the world. Here is just one of those stories.
A long , long time ago there was a man called Noah(诺亚). He lived with his wife, his three sons and his sons’ wives. One day, Noah heard a voice. It said: “Noah, soon there will be a big flood. You must build a boat. You must put two of every animal and bird in the boat. Many, many people will die in the flood but you and your family will be all right.”
Noah and his family built a boat. They put two of every animal and bird in their boat. They put food in the boat, too. Then it started to rain. It rained for 40 days and 40 nights. The water covered the world. The hills and mountains looked like islands. Noah’s boat stopped on the top of the mountain. At last the rain stopped and the flood went away. There was a beautiful rainbow in the sky. And the animals and birds left Noah’s boat. They ran, jumped, walked and flew away to live on the mountains.
According to the story, answer the following questions:
Can floods be good for farmers?
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What did Noah build to protect his family from the flood?
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How long did the rain last?
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