书城外语课外英语-动物亮丽风景线(双语版)
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第39章 幼兽怎样出生?

A female kangaroo usually gives birth once a year.All kangaroos except the musky rat kangaroo have one joey.The musky rat kangaroo usually has two.Some kangaroo species living in dry regions mate whenever there is enough food and water.These kangaroos may have no litters for several years if there is a drought.

A baby kangaroo is still undeveloped when it is born.The tiny animal weighs about 0.04ounce (1gram).It has no hair and cannot see.It crawls along its mother’s body and into the pouch.Once inside,the baby attaches to a nipple and sucks milk.It stays in the pouch for several months.Even after the joey can move about on its own,it may stay with its mother until it is more than a year old.

Large kangaroos live from 12to 18years in the wild.They do not live as long if there is a long drought.In captivity with plenty of food and water,large kangaroos can live up to 28years.Smaller kangaroos have shorter lives.

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