____________ in the company for three years, Mark has become experienced in business negotiations.

______ a river on land, an ocean current does not flow in a straight line.

_______ is known to the world, Mark Twain is a great American writer.

One rainy night, the policeman had a chance ________ with a gang of smugglers.

Anderson is one of those ________ appear friendly but in fact are hard to deal with.

There is no doubt ________ Herbert is the most industrious student in our class.

Look at the clock! It＇s time _________ work.

The representative of the company demanded that part of the agreement ________ revised.

I tried hard, but I couldn＇t find the______to the problem.

This company has two branches: one in Paris and _________ in New York.

Jack＇s train _________ at 50＇clock next afternoon, let＇s go to see him off.