There is a teacher’s desk _______ the classroom. Mr. Liu is standing _______ it.
--- ______ do you play football? --- Once a week.
Hurry up, ______ you will miss the plane.
Both my parents were born ______ 1970.
I’m talking to you, Jack. Please listen to ______ carefully.
--- Do you know ______ tomorrow? --- At 8 o'clock.