Not until a student has mastered algebra .... the principles of geometry, trigonometry, and physics.
Sally was sad and felt as if the whole world .... her enemy.
.... the air fares have gone up, many people still prefer to travel by plane.
It is the recommendation of many psychologists .... to associate words and remember names.
The people in this region have been considering .... themselves from the rest of the country.
I think I had better .... my thesis soon since I will be busy in the coming semester.
Carl Sandburg, ...., is also well known for his multivolume biography of Lincoln.