When I walk_____ the classroom, all the students are listening carefully. [ ]

Tom can’t find his gloves. Are these blue gloves his?—No, they _ be his. His gloves are black.

______ his bike is lost? — He has to go to school on foot.

Will you please go to see the movie Guanyinshan with me tonight? —No, I won’t. I _________it many times.

My birthday is _____ September 13th.[ ]