The number of people invited _________ fifty, but a number of them _________ absent for different reasons.

Do you remember those days _______ we spent together along the seashore very happily?

---“Each of the students, working hard at his or her lessons,_____ to go to university.” ----“So do I.”

At present, one of the arguments in favor of the new airport ________ that it will bring a lot jobs to the area. 

“I_______ a teacher, you_______ a student, your father_______ a worker", Mrs. Wang says to Jill.