—Look! Mark is reading a book in the library.
—It ________ be him. He is in the classroom.
can’t
wouldn’t
needn’t
I don’t know _________.
The MP3 ______ too much. He ______ 200 yuan _______ it .
The art club is for members only. You can’t go in _______ you are a member.
She likes doing her homework _______ the radio _______.
In winter, we must pay attention to _________.