题目内容：

阅读短文，从方框中选择适当的单词填空。

themselves     lions      sad     in     food

Many people may think that animals in the zoo are happy and lucky, but most of them are 1.           . Do you know why?  Animals like tigers, 2.____________ and bears usually live in forests or mountains. They run, jump, play with their children and find small animals for3.          . But now they have to stay in small rooms4.        the zoo. They don’t have to find food by 5.           because the zookeepers feed them.