few years, the coal workers___________ their lungs X-rayed to ensure their health.

There is much chance ________ Bill will recover from his injury in time for the race.

I remember I have been here before There used to be a church near the park, _______?

I am sorry to have kept you ___________.—It doesn’t matter. I’ve just come.

It is reported that the United States uses _____ energy as the whole of Europe.