Living in a house on a mountain top ______ be rather cold, especially in winter.

---Could I borrow your dictionary?
----Yes, of course, you               .

You______ her in her office last Friday; she's been out of town for two weeks.

Our world ___________ to live in without so much pollution．

--- Where will you start your work after graduation?
--- Mmm, it’s not been decided yet．I _______ continue my study for a higher degree．

— Hi, Johnson, any idea where Susan is ?
— It’s class time, so she          in the classroom now.

The chemistry teacher demanded that the laboratory report _______ immediately after the experiment was done.

--- Has Li Lei finished his work today?
--- I have no idea, but he ______ it when I saw him this morning.

— My sons are not a little restless．
— Oh? Boys _______ be boys．

— Why didn’t you give a hand to the boy?
— I _______, but he struggled to his feet before I tried to．