4．听下面一段独白，回答第17至20小题 17．What did the mother lock the door with three locks for every night？ A．Because the door was not strong enough． B．Because her daughter asked her to do so． C．Because she thought a thief would come in． 18．Why did the daughter leave home one day？ A．She didn't love her mother at all． B．She thought her life was boring． C．Her mother didn't lock the door that day． 19．How did the girl feel when she came back？ A．Tired and surprised．B．Afraid and surprised．C．Tired and afraid． 20．What can we know from the passage？ A．The daughter knew the door wasn't locked before she came back． B．The mother loved her daughter very much． C．The daughter liked the outside world best．
