The volunteers sent _______ books to amountain village school on Children’s Day.

This is the second time I by him;I shall never trust him again. [ ]

－Why did you arrive late?(成都市)－The fog_______ our air flight for about half an hour.

He pretended to be a doctor, but ________ he is a cheat.[ ]

Ladies and gentlemen, welcome to my program. ______ me this evening is Dr. Gray. [ ]