At the railway station, the mother waved goodbye to her daughter until the train was _______.
__________ in the queue for half an hour, the old man suddenly realized he had left the cheque in the car.
__________ at my classmates' faces, I read the same excitement in their eyes.
__________ is known to everybody , light travels faster than sound.
This kind of ancient book requires a great deal of .
—My deskmate accused me breaking her glasses. —Oh,you had the right to defend yourself her accusation.