I _________ here earlier, but I couldn’t catch the first bus.

―Is that Miss Liu having dinner over there?―It     be her. She has gone to New York for an important business meeting.

I didn't see your sister at the party. If she __, she would have met my brother.

He ______ the key, so we ______ into the office.

—Are you coming to Jeff’s party?—I’m not sure. I__________ go to the concert instead.