1. Why are you leaving so soon?
2.The flight attendent took off the tray cover before the plane took off
3.They could not be heard because of the noise
4.There are too many people in that small room
5.The professor has a class on Monday at three o'clock in the afternoon
6.In the test William is going to write about his teacher
7.We should always be careful to express ourselves properly
8.Who is going to pay for the ticket?
9.How many guests do they think will come ?