题目内容：

（共5小题，计10分）阅读下面的材料，然后根据材料内容回答问题。

There are about forty-seven different kinds of kangaroos(袋鼠) in the world. The smallest are about a fourth of a meter long; the biggest are taller than a man. Kangaroos have very long strong back legs. These are for jumping. They also have long strong tails(尾巴) to rest on. Kangaroos’ front legs are much shorter, and are almost like arms. Kangaroos’ heads are quite small, but their ears are quite large.Mother kangaroos have a pocket at the front. They have one baby each year. When the baby is born, it is straight into its mother’s pocket. The baby kangaroos stay there for six months.The biggest kangaroos stand more than two meters tall, and their legs are so strong that they can jump more than nine meters. They are very fast, and can travel at more than 50 kilometers an hour. They are very strong, but they only eat fruit, leaves and grass.

1.How many kinds of kangaroos are there in the world?

2.Are their front legs as long as their back legs?

3.How long do baby kangaroos stay in their mothers’ pockets?

4.Why can the biggest kangaroos jump more than nine  meters?

5.What do kangaroos eat?