Penicillin was then produced ________ in order to meet the demands of the armies.

Mr. Wang would have continued to lead _____ poor life instead of changing his lifestyle if he hadn’t met Mr. Smith by _____ chance who was a businessman.

This is ________apple, and that is ________ orange.

____ do you do on Halloween — We play games and have lots of fun.

China Dream is a great way to gather people together and ______the fast development of our country.