—You look so worried.What’s the matter?—I don’t know________these boring problems.
The two boys fought and fought until one ______.
He will _____ our class to sing at the school singing contest.
John _____ knowledge of radio just by staying around the radio station.
It isn't so much whether he works hard; the question is whether he works _____.
When I took his temperature, it was two degrees above _____.