For passengers traveling into the city, taxis and car services charge ________ 50 dollars.

Just as a book is often judged ______ by the quality and appearance of its cover, a person is judged immediately by his appearance.

The mother looked at the door _______，expecting the children’s coming．

Since production has risen ________, the personal income has increased year by year.

Though it was in the midnight, ________ there were a lot of people in the street.

I can't believe what he says because he is _______ changing his mind. .

Professor Lee failed many times but he ________found a good way to solve the problem.

Young children seem to master computer games __________. And playing computer games will always make them feel ___________.

When you feel you are happier and more relaxed after having a cigarette, you may become ________addicted.

After two years’ study, he now has a __________ better command of English.