19- Compared to the author of Passage A, the author of Passage B provides more information about the:


  • A-reduction in the number of apple varieties in North America over the past four centuries.

  • B-methods Vavilov used to prove to other scientists that the apples growing in the Tian Shan are the ancestors of the modern apple.

  • C-number of apple varieties that are thriving in Kazakhstan today.

  • D-techniques used by researchers to determine the regions with the greatest genetic diversity in plants.