There was a big dog ______ in front of Mr. Hill’s house, so David didn’t dare to go near it.
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.
In a chemical change, energy cannot be created ,____.