a bird in a cage的用法和样例：
- Is it cruel to confine a bird in a cage?
- Be it cruel to confine a bird in a cage.
- It is not good to confine a wild bird in a cage.
- A believer is a bird in a cage ,a freethinker is an eagle parting the clouds with tireless wing .
- He was confined by the emperor, living like a fish in a pond or a bird in a cage.