Where on earth have you been? We you back much earlier.
—Where ________ Mary have put the empty bottles? —She ________ them away. They must be somewhere.
Some young people these days just ________ go out of their homes to contact the real world.
—Who ________ be phoning us at this time of night? —It might be your sister.
—John looks a bit upset. Did you tell him the bad news? —Yes, but I ________ him after his birthday party.
Sometimes smiles ________ be false, hiding other feelings like anger, fear or worry.