_____ is no doubt ______ you have to remain seated and fasten your seatbelt before the plane lands.
After he had said good-bye to Jack, Tom ______ a bus and left the town.
When I entered the classroom, I saw the students _____ in their seats.
I would really _____ it if you could offer me the chance to study abroad.
I wonder how he _______ that to the teacher.
My grandfather spends most of his time _______ because he loves nature.