Lizzie was______ to see her friend off at the airport

We cannot figure out ______ quite a numberof students were infected with the flu.

35Not until the train pulled into the next station ______ that his briefcase had gone

Li Lei isn’t in the classroom. Where is he—He to the teacher’s office.

May Day is coming up. Have you decided ________— I’m planning to go on a trip to Hangzhou.