Jim, read books while you are walking in the street. It’s very dangerous.—OK, thank you.

What does the sign over there say?–No person ______ enter the area without official permission.[ ]

下列各句中，没有语病、句意明确的一项是

already 18 years old, but she _____as if she were still a little girl

I can’t leave. She told me that I _______ stay here until she comes back.