試題詳解

49
(A)Now some of the other candidates have begun to emerge.
(B)Life spans are nothing like a trait such as height, which is mainly inherited.
(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.