48
(A)Now some of the other candidates have begun to emerge.
(B)So these days, when it comes to life span, many people try to think of some long-lived family members.
(C)That means it is generally impossible to predict how long a person will live based on how long the person’s relatives lived.
(D)Also, they may be simply chance events, like a randomly occurring mutation in a gene of a cell that ultimately leads to cancer.