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第1段
1 .<-NARRATOR:-> Now listen to part of a lecture on this topic in a biology class.
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第2段
1 .<-MALE PROFESSOR:-> Okay, so here's a good example of this among ants.
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2 .Ants live together in these large nests,
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3 .and certain ants, the forager ants,
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4 .have a particular job to do-
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5 .they go out each day to look for food items... leaves, seeds, fruit...
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6 .things like that... and then these ants bring them back to the nest
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7 .so all the other ants can eat them.
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第3段
1 .Now the forager ants don't just bring back whatever they may happen to find;
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2 .they bring back different kinds of food.
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3 .For example, adult ants normally like to eat things that are rich in sugar
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4 .because they need energy to carry on other activities in the nest.
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5 .So at a time when the colony is composed mostly of adult ants,
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6 .the forager ants look for pieces of fruit and other sugar-rich items.
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7 .They bring these back to the nest
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8 .for the adult ants to eat to get the energy they need.
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第4段
1 .But there is a time of the year when baby ants are born.
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2 .Now, the baby ants need a different kind of food.
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3 .They need food that will help them grow into adults.
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4 .So their food needs to be rich in protein.
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5 .So now the forager ants do something different.
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6 .They start to gather more food items that are rich in protein, like certain types of leaves, or mushrooms.
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7 .This way the young ants get the protein they need to help them grow.
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