综合填空。
用适当的词完成句子，使短文意思完整。
There are 47 different kinds of Kangaroos (袋鼠). The smallest are about a quarter of a meter long. The
1. _____ are taller than a man. Kangaroos have very long strong back 2. _____. These are used for 3._____ .
They also have 4. _____ strong tails for resting on.
Kangaroos' front legs are 5 ._____shorter, and are almost like arms. Kangaroos'
