____ wide spread of H1N1 is _____ challenge for the whole world. Confidence, cooperation and responsibility are keys to overcoming it.
The international agreement, ______ to encourage children not to smoke and help people kick the habit, was signed on February 27.
― Why ______ you stay in the countryside, where it’s not convenient to go shopping? ―But I’ve found it rather valuable for my health.
The view ____ many scientists hold is ____ too much emission of carbon dioxide is destructive.
_____ this afternoon, you would have to come again next week.
It is reported that some wild animals were found_______ in a big cave in the mountain.