— It’s the office! So you ______   know eating is not allowed here.— Oh, sorry.

—I don’t think you should use the dictionary while reading newspapers.—      , but I can’t do without it.                                         

Look! If we had begun to do the work yesterday morning, we _____ ourselves just like them．

Mountain climbing _______ be tiring and many people feel sick as the atmosphere gets thinner.

He___ have attended the meeting this morning. He has been staying at my home for a whole day.