Mr.Smith was blind when he was seven. He had seen many doctors but none of them could do anything for him. He could never see the world again . Now he has a seeing-eye dog. A seeing-eye dog can help a blind man walk along the streets. It’s very useful for his live.
( )1. Mr.Smith was blind when he was six.
( )2. He could never see the world again .
( )3. He hadn’t seen doctors
( )4. A seeing-eye dog can help him walk along the streets.