When about one of the biggest problems today, many experts say that an energy crisis is approaching and is thus threatening mankind's survival.
“I hope you don’t mind my pointing out your mistake.” “____”
Talking about the future career, I’d prefer ___ a teacher ___ be a secretary.
I can’t ___ him doing a thing like that.
Was it near the bridge ____ the car accident took place?
___in the air, this kind of steel become harder and harder.