用合适词的正确形式填空。每空一词。

       Animals are our    1   . We can find different kinds of    2   in the world.   3   animals only eat grass,

for example, elephants and cows. And some animals only eat   4   , for example, tigers and lions. Animals

can   5   many things for people. For example, elephants can help people   6  some heavy(重) work.

Children like    7  very much, so they often play   8   dogs. They think dogs    9  very clever. Boys and

girls, what animas     10   you like?