You must concentrate more _________ your English.
He looks upset. He doesn’t know ________.
Mrs. Smith eats _______ meat, so he is ________ fat now.
There are about two ________ students in the new-built school.
--Peter, don’t play that kind of jokes any more?--Sorry, I ________ do it again.
He isn’t ________his father, but he ______his father very much..