Which of the following is true according to Paragraph 2?
A．Chronic diseases are complex genetic puzzles to scientists.
B．How exceptional longevity-related genes function is known.
C．Most centenarians have exceptional longevity-related genes.
D．The integration of genes and environmental factors is important.

A.Chronic
B.
B．How
C.
C．Most
D.
D．The
E.


【参考答案】

C
推理判断题。第二段①句后半部分提到，90％的特别长寿者都至少拥有一种与长寿有关的标志基因图谱，可见C项与之最为贴近。