重点讲解：
1. be happy to do sth.
乐意的；情愿的；
eg. I'll be happy to meet him when I have time.
我有空的时候，很乐意同他见面。
eg. I will be happy to do it for you.
我乐意为你效劳。
2. get around
到处旅行；游历；
eg. He claimed to be a journalist, and he got around.
他自称是一名记者，经常四处游历。
eg. I get around town on the hus.
我到城里的任何地方，都是搭乘公交车。
3. depend on
取决（于）；有赖（于）；
eg. It would depend on the circumstances.
这要视情况而定。
eg. This shift is rapid and does not depend on natural selection.
这种变迁的过程很快而且并不取决于自然选择。
