The man we followed suddenly stopped and looked as if ________ whether he was going in the right direction.

Only ________ according to the directions can the medicine be quite effective.

—We didn't find the Blacks ________ the lecture.—No one had told him about ________ a lecture the following day.

A few days after the interview，I recevied a letter ________ me admission to the university.

—Why do you look sad?—There are so many problems ________.

________ as the “first lady of speech”，Dr, Lillian Glass is recognized as one of the world's leading experts on communication skills.

John received an invitation to dinner，and with his work ________，he gladly accepted it.

—Come on，please give me some ideas about the project.—Sorry.With so much work ________ my mind，I almost break down.

The country has already sent up three unmanned spacecraft，the most recent ________ at the end of last March.

________ the program，they have to stay there for another two weeks.

The news of ________ greatly made us surprised a lot as he was indeed very excellent.

 —They are quiet，aren't they?—Yes.They are accustomed ________ at meals.

 ________ the meeting himself gave them a great deal of encouragement.

The flu is believed ________ by viruses that like to reproduce in the cell inside the human nose and throat.

—Is Bob still performing?—I'm afraid not.He is said ________ the stage already as he has become an official.

When I handed the report to John，he said that George was the person ________.

In my opinion，life in the twenty－first century is much easier than ________.

 —What's the matter with Della?—Well，her parents wouldn't allow her to go to the party，but she still ________.

To fetch water before breakfast seemed to me a rule ________.

________ from media reports，the result has been unclear.