In many American universities, the total work for a degree thirty-six courses, each for one semester(学期).
Some researchers are finding that daydreaming may be important to ______ mental health. Daydreaming, they say, is ______ good means of relaxation.
―Shall I invite Tom to my party? ―Yes. It’ll be nice if you .
The little boy the last bit of toothpaste from the tube.
When trees are cut down, there is nothing to hold the soil on the hillside.
On his way home, he suddenly heard his name .