The factory ______ its waste into the river, but now it deals with the waste in a new way.

You ________ be hungry already — you had lunch only two hours ago!

--The man in a black suit _______ be our youth worker. -- I’m sure it _____ be him. I saw him in the laboratory building some minutes ago.            

If the green light doesn’t come on, you ______ go across the street.

Days later, my brother called to say he was all right, but _______say where he was.