You can’t imagine ______ when they received these nice Christmas presents.

How long ____ was this? — It’s been nearly six years now

ay find the key to the math problem onpage 107.—Ah, it’s so simple. I wonder why I _____ ofthat.

27. —-Can I catch a train to Beijing? —-You _____miss one. There are many trains to Beijing.

Why do you want the book—- _________, sir.