---Whose pens are there? --They are ____. They aren’t ____.
The number of foreign students attending Chinese universities ________ rising steadily since1990.
---- Could you do me a favor and take the box up to the sixth floor?---- __ ____. No problem at all.
----You’ve never been to the village, have you? ----__ __. It is the most beautiful village I’ve ever seen.
If it had been possible, I would have helped him, but I ______ too busy.
He was so angry at all _____ I was doing _______ he walked out.