Penguins （企鹅） live together ,but each pair has a little piece of ground of their own.When a penguin wants to walk through its neighbor's ground ,it must ask permission （允许） .If it does not do that ,it will have to fight.Most of the time ,penguins live on the water.They eat shellfish and look after their children carefully.
All penguins are good parents—the male penguins are perhaps the best parents in the world.They walk in from the sea in the middle of the dark Antarctic water.They choose their wives in the dark.They can only hear them—not see them.
他们从黑暗的南极水域中间的海里走进来.
句子分析：
主语：they
谓语：walk in
状语：from the sea
定语：in the middle of the dark Antarctic water