Boys and girls, please have a seat and ____.—Thank you.

What’s this _____? －It’s a hat.[ ]

“I’d like to give my thanks to those__________help my son will be able to survive his terrible disease,” said the woman on TV.

The earthquake in Japan, measuring 9.0 on the Richter Scale, was so violent cause a series of explosions of the nuclear reactors in several power stations.

If we __________ careful，fire can be dangerous。