The novels written by the author sell best, but five years ago no one could have imagined how great a role he     in the literary world.

—Flight 331 _____．I'd better be on my way．Goodbye．
—Bye．Happy landing!

32.So often ______ in recent years that it has almost become a rule.

25. ------- What’s that noise?
--------- Oh, I forgot to tell you. The new machine ____________.

33. Nowadays, use____of certain waste materials to protect the environment.

31. How to solve the problem __________ in the meeting right now

34.---You may find the key to the maths problem on page 107 .
---Ah, it’s so simple . I wonder why I___________of that .

23.Mr. Li_____a secretary for five years in the company, and now he is the general manager of it.

— I saw your uncle take a taxi to the airport. Why didn’t you drive him there?
— I ________. But my car ________.

— Have you seen my email about our TESL project?
— Yes. Luckily, I checked my emails yesterday. Normally, I _____ my email-box for days.