He told us he _______a concert________.

I soon found that the work I was doing ____ by someone else — in other words, I was wasting my time.

The teacher said that Columbus _______America in 1492.

Mr. Li is absent today. What do you consider ________ to him?

—Where are the guests to be from tomorrow?
—Many an American boy and many a British girl as well as the teachers to he present.

    He made it clear that only the point that new technologies hold the key to increasing productivity     the economy in the long run.

Watching the online open courses of some famous European and American universities _______a new fashion among white collars in China over the past few months.

——Can you give me some advice on what I said just now?
—— Sorry, my mind ______ .

When I finally got up to leave, we both knew that a real friendship ________ between us

— Why, David, you look so tired!
— Well, I ________an article and I must finish it tomorrow.