____you had worked hard, you would have easily passed the final test.
John seems puzzled about ________ the question meant.
All his free time is ______ by volunteer work, but he feels it meaningful.
The athletes competed ________ each other for gold medals in the Olympic Games.
--Can a plane fly ________ the Atlantic Ocean?--Yes, but it needs to go________ the clouds for hours.
The room ___________ window is open is mine.