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为了飞翔,鸟儿必须使羽毛保持整洁。如果羽毛上沾上黏性物质,鸟儿就用它们的尖喙来梳理,从羽毛根部一直仔细地梳理到末端。如果身上有
In order to fly, the birds must keep their feathers tidy. If the feathers are covered with a sticky substance, the birds comb their feathers and carefully comb the ends of the feathers. If you have