26. The leaves of this tree turn red ____ , so we visit it at the end of every October.
As soon as his teacher begins lecturing, he begins to doze off, not intentionally but _____.
The Chinese lunar New Year usually _____ two records: the world's most watched television gala show, and its busiest telecommunications network.
Nowadays certain limit should be set on use of cars to reduce air pollution.
All teachers received warmest congratulations on Teachers’ Day. They felt ________.
A group of Chinese guests, who are the first ________ from the new agreement on tourism between China and Switzerland, were given a warm welcome in Geneva(日内瓦) last Saturday.