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

Students ought ______ the truth.

— Who’s that man in our classroom? It ________ be Mr. Brown. He is much taller.— You mean the man in white? He is an exchange student from England.

According to the rules and regulations, all payments ________ be made in cash in the shopping center.

Sometimes we have much homework to do, but not often. Anyway, it ______in time.