填空题 A) phenomena
   B) priority
   C) preference
   D) suspicious
   E) controversial
   F) dominant
   G) attributes
   H) assets
   I) evolution
   J) commenced
   K) advanced
   L) scatters
   M) sheds
   N) exist
   O) survive
   I have read The History and Geography of Human Genes by Luca Cavalli-Sforza but still have some questions. Even though the findings seemingly prove that races are essentially equal on a genetic level, there are differences unexplained. It was Darwin who first (1) the theory of natural selection. His notion was that certain characteristics that help that species (2) are selected over generations by that species. The species does not consciously make the choice for genetic (3) Instead, by surviving longer and being more fruitful, members of that species with the preferred genes gradually become the (4) breed. We may, as a species, all have (5) our existence in one location, but this was long long ago. Factors such as climate and other survival necessities have created needs for (6) . I believe these factors have contributed to races evolving with different (7) . This explains the (8) such as Asians receiving better science and math scores. It also (9) light on why there are so many excellent athletes from Africa. I understand that this is a particularly (10) statement. This is especially true in an age when races are mixing and the peoples of this planet are attempting to learn to live together.