1.   Both theories are based on a single wrong assumption.

2.   The chapter showed that these theories are based on microeconomic foundations.

3.   Asked to assess the best and worst tippers, valets base their theories more on cars than the way a customer looks or acts.

4.   But nothing has ever been proven, and all the theories are based on small numbers, small enough to be chalked up to chance.

5.   But they were quick to point out that this theory was based more on a general sense of the dynamics of an ossified government than on any concrete signs.

6.   Even the critics based their theories on the photos.

7.   For most of its history, astronomy was a strictly observational science, and earlier astrophysicists based their theories largely on what astronomers could see.

8.   His theory is based on the idea that Early Man hid himself in order to hunt.

9.   I believe his theory is not based on a realistic assessment or a realistic approach.