Betty and Arthur ____ on separate holidays in a few days’ time.

The mother didn't know who      the glass because it happened when she was out.

–Why, Jack, you look so tired!
--Well, I ___the house and I must finish the work tomorrow.

With the help of high technology, more and more new substances ___in the past few years.

The number of the people who own cars ______since 1990.

It is the first time that I ______ this kind of moon cake.

Edward, you play so well, but I          you played the piano.

My headache _____ me．I thought it was going away, but it’s getting worse and worse．

Although some athletes _______ their sports ambitions , there are still many more struggling for success .

Some wild animals _____ and killed at such a speed that they will disappear from the earth in the near future.