The sign "THIS SIDE UP"is often seen ________.

A. on a box

B. in the street

C. at a police station

D. at a post office

The sign“THIS SIDE UP”is often seen_________.

A. in a book      B. at a theatre     C. on a box     D. in the street

The sign“THIS SIDE UP”is often seen________．

A．in the street  B．on a box   C．at the police station   D．on a door