The number of students in our school _________ 4000 and a number of them _______ good at playing Ping-Pong.A. is, is B are, areC. is, are D. are, is
—How soon will you finish your homework?—________ an hour.
The reporter said that the UFO ________ from north to south when he saw it.
Hurry up, everyone ________ for you.
Trees __________ on Tree Planting Day only.
Sorry, smoking ________ here.