Reading and examination of the sentences allows one to state that they all share:

1. Whether you earn an A or get a lower grade, do your best.

2. Both John and Bill are excellent tennis players.

3.Neither the professor nor the students understood the problem.

4. I not only lost the game but also hurt my ankle. 5. Professor Jenkins is not only patient, but also stimulating.

6.Hector did not lose money at the casino but he did not win any either.

7. Barbara is as tall as Mary.