Here are 20 sentences. Each sentence contains ONE mistake. We have underlined four possible mistakes in each sentence. Your job? Find the mistake in each sentence.

1. Interest in automatic data processing has grown rapid since the first large calculators were introduced in 1950.

2. Vaslav Nijinsky achieved world recognition as both a dancer as well as a choreographer.

3. Airports must be located near to major population centers for the convenience of air travelers.

4. It is said that Einstein felt very badly about the application of his theories to the creation of weapons of war.

5. The plants that they belong to the family of fems are quite varied in their size and structure.

6. Despite of the increase in air fares, most people still prefer to travel by plane.

7. All of we students must have an identification card in order to check books out of the library.

8. Columbus Day is celebrated on the twelve of October because on that day in 1492, Christopher Columbus first landed in the Americas.

9. This vase has the same design, but it is different shaped from that one.

10. An unexpected raise in the cost of living as well as a decline in employment opportunities has resulted in the rapid creation by Congress of new government programs for the unemployed.

11. It is imperative that a graduate student maintains a grade point average of "B" in his major field.

12. Because of the approaching storm, the wind began to blow hard and the sky looked as evening.

13. Economists have tried to discourage the use of the phrase "underdeveloped nation" and encouraging the more accurate phrase "developing nation" in order to suggest an ongoing process.

14. A good artist like a good engineer learns from their mistakes in order to improve.

15. After he had ran for half a mile, he passed the stick to the next runner.

16. Regardless of your teaching method, the objective of any conversation class should be for the students to practice speaking words.

17. A City University professor reported that he discovers a vaccine that has been 80 percent effective in reducing the instances of tooth decay among small children.

18. American baseball teams, once the only contenders for the world championship, are now being challenged by Japanese teams and Venezuelan teams.

19. When they have been frightened, as, for example, by an electrical storm, dairy cows may refuse giving milk.