I don’t know who invented ________ telephone. It’s really ________ most useful invention.
If you are inposition of __ teacher, will you allow your students to play computer games all day long?
Once __________sport has become less popular, it has to make __________way for new sport which are more popular to enter into the Olympics.
—I was caught in the heavy rain, so I couldn’t be back by 7 o’clock. —__________! Janna was here to see you.
Either you or one of your family members __________the opening ceremony next week.
Our class discussed the question of __________it is necessary for us students to use mobile phones on campus.