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(单词翻译)
This is Scientific American's 60-Second Science. I’m Karen Hopkin. It’ll just take a minute.
When you think about an ecosystem1, you usually think of the big animals that live there. The Serengeti’s ruled by lions. And estuaries2 are populated by fishes, birds, snails3 and maybe the occasional otter4. But there’s more to an ecosystem than meets the eye. Because a team of scientists from the US and Mexico has found that parasites5 constitute a sizeable chunk6 of the biomass of an ecosystem. The scientists catalogued and weighed all of the plants, animals and parasitic7 species living in three river estuaries. They found that in terms of sheer bulk, parasites represent about three percent of the biomass of these ecosystems8. Pound for pound, one parasite—the trematode fluke that infects a certain snail—outweighs all of the estuaries’ birds, which are the ecosystem’s top predators9. The results appear in the July 24 issue of Nature. That means that creatures you can’t see might be even more important to the health of an ecosystem, and to its balance of power, than the ones you can see. For example, in these estuaries, snails that are infected with trematodes outnumber those that are fluke-free. Now that’s what you call a controlling interest.
Thanks for the minute for Scientific American's 60-Second Science. I’m Karen Hopkin
1 ecosystem | |
n.生态系统 | |
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2 estuaries | |
(江河入海的)河口,河口湾( estuary的名词复数 ) | |
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3 snails | |
n.蜗牛;迟钝的人;蜗牛( snail的名词复数 ) | |
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4 otter | |
n.水獭 | |
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5 parasites | |
寄生物( parasite的名词复数 ); 靠他人为生的人; 诸虫 | |
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6 chunk | |
n.厚片,大块,相当大的部分(数量) | |
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7 parasitic | |
adj.寄生的 | |
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8 ecosystems | |
n.生态系统( ecosystem的名词复数 ) | |
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9 predators | |
n.食肉动物( predator的名词复数 );奴役他人者(尤指在财务或性关系方面) | |
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