11.   For reasons scientists do not understand, the doctor apparently did not spread the virus to others.

12.   For reasons that are not fully understood by scientists, adult tuna in the rich fishing grounds of the eastern Pacific tend to congregate underneath dolphins.

13.   He envisions a whole series of medical breakthroughs as new technologies allow scientists to better understand the unique physiological adaptations behind the diving feats.

14.   Moreover, he said, animal experiments also indicate that olive oil somehow protects against chemically induced breast cancer, although scientists do not understand how.

15.   Once scientists understand the specific protein involved in a disease, they can start to look for the molecule that controls it.

16.   Progress in preventing mental illness has been slow, because scientists do not understand enough about the causes of such illness, the report said.

17.   Problems in gene development lead to high rates of death and deformity in cloned animals, for reasons that scientists scarcely understand and have little means of preventing.

18.   Researchers concluded that strict controls were needed on such experiments until scientists understood the implications.

19.   Scientists understand that the El Nino starts with a general warming of the waters of the Eastern Pacific off the coast of South American.

20.   See, I told you the scientists would understand.