—Why are your eyes so red？You________have slept well last night.—Yeah，I stayed up late writing a report.                          (

---There’s someone knocking on the door. Who _________ it be?---It must be John. He promised to be here at 8:00.

---Is that Lucy’s sister, Lily?---No, it _______ be her. She has gone to English.

— Happy birthday!— Thank you! It’s the best present I _______ for.

In China when the traffic light is red, you ________ cross the road.