There are some trees on one side of the road and some factories on _____.
--How do you like the twins? --Well, I think the elder sister is _______ but the young sister is _______.
--- There were so many books in the shopping center, I didn't know_______ .
Put on your coat, Jack! It's snowing _______ outside at the moment.
—Is that Tom in the teachers' office? --No, it ________ be him. He's gone to the hospital.
Last night, Dan hung out with his friends too late. When he came home, he went upstairs without a _______. But to his surprise, his father was sitting in his room.