根据句意提示写单词1.Why is the dog____all the time?-I guess it sees a

根据句意提示写单词
1.Why is the dog____all the time?
-I guess it sees a stranger.
2.Look!The boy is walking on a rope.
-It is not easy to keep his_____________.
3.We often see this sign in some big buildings.It means there is an_________nearby.
4.The girl is making a face at others by holding her____out.