听力原文： The elephant is the biggest four-legged animal in the world. It is also, perhaps, the gentlest; but not always!
Elephants are like us in some ways. They live for a long time—fifty or sixty years. They can remember things very well. They never forget great sadness or great happiness. When a female elephant dies, her daughters and her granddaughters are sad for many months. They stay with the dead body. Then they carry a bit of it away with them. They never forget a dear friend.
Elephants are like us, but they are also different. They live in families; families of females. There will be a few young males—a few "baby boys". But the females will soon send them away. An elephant family keeps only its daughters, mothers and grandmothers, and its great-grandmothers.
The females stay together for fifty, sixty...a hundred years. The older animals look after the younger ones. The mothers teach their daughters and set a good example.
And what happens to male elephants？ Well, the young males stay with their mothers for a time. Then they must leave the family. The females just send them away. A bull elephant does not often have a friend. He lives apart; away from the family, and often away from other bulls.
Sometimes the females call a bull. He can visit them then, and stay for a time. But soon his "wives" and sisters send him away again. The females have a very happy family life. What do the bulls think about it？ We don't know.
(33)

A. Twenty years.
B. Forty years.
C. Sixty years.
D. Eighty year.