1.   Every researcher knows that a clear understanding of terms and concepts is necessary in order to communicate to other scientists and scholars.

2.   Although a lot of what happens during sleep is not known, researchers do know that the body repairs itself.

3.   Because the researchers do not know how to manipulate embryonic stem cells from cows, they let the cow embryos develop into fetuses, Lanza said.

4.   A better target, researchers knew, would be stem cells.

5.   According to Hampl, researchers have long known that smokers have bad diets.

6.   But at first, the researchers did not know whether any of the women had BRCA mutations.

7.   But beyond that, researchers know very little.

8.   But Gibbons said the researchers do not know if the cells will be of any greater therapeutic benefit than those already in existence.

9.   But company researchers also know how to create molecules that hunt proteins in the bloodstream that cause rheumatoid arthritis, allergies, asthma and solid cancerous tumors.

10.   But most of the lung cancer information was gleaned from death certificates, so it was impossible for researchers to know whether those women smoked.