1. 用方框内所给词组的适当形式填空。

get lost, cut down, walk on, made of, in danger

1. （1） As we know, dogs never  after they walk a long way.
3. （2） How smart the dog is! It can  two legs.
5. （3） Some animals are . We have to make rules to save them.
7. （4） We mustn't buy things  ivory to save elephants.
9. （5） People can't  so many trees any longer. Animals are losing homes.