Summary: In the animal world, many multicellular animals have cancer but sharks never get cancer.

在生物界中，只有多细胞动物得癌症。偏偏沙鱼不得癌症。

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Not only did mammals sweep across the planet after K-T, but sharks expanded across the seas, explained American Museum of Natural History vertebrate paleontologist Jack Conrad.

美国自然历史博物馆脊椎古生物学家Jack Conrad解释说，k - T大灭绝之后，不但哺乳动物开始主宰地球，鲨鱼也开始在海洋中扩张。

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They didn't see any seals, but they saw some sharks.

他们没有看到海豹，但是他们看到了一些鲨鱼。

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But he says in fact, sharks are very shy creatures that do not like to attack humans.

VOA: special.2009.04.03

But Senator Lee says not all sharks are in danger of extinction.

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But few people are afraid of elephants as they are of sharks.

VOA: special.2009.04.03

Whales are very important but sharks are more fundamental to the survival of our oceans, healthy oceans than whales probably ever will be.

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Five years ago, the National Marine Fisheries Service instituted a fishery management plan to prevent overfishing of sharks in federal waters but the sharks aren't seeing the lines, apparently, and move in and out of federal waters and get caught in state waters where they aren't protected.

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But the sharks are spotted, and the pattern of spots varies from shark to shark.

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