---Who’s the man over there? Is it Mr. Black?--- It _________ be him. He’s much taller.
We are told ________ everywhere. It’s our duty to keep our school clean.
---Mind your steps, guy! Don’t you see the words “__________ the grass”?
Nobody can learn English well __________he works hard on it.
I agree with most of what you said ,but I don’t agree with _______.
The ice changed ____ water ____ warm air around .