【单选题】

Most of us think we know the kind of kid who becomes a killer, and most of the time we’re right.Boys (31) about 85% of all youth murderers, and in those cases about 90% fall within a pattern (32) the line from bad parenting and bad (33) to murder is usually clear. Their lives start with abuse, neglect and (34) deprivation at home.Add the effects of poverty and drug, and it is not (35) that in a violent society like ours, (36) children become deadly teens.

(37) what about the other 10% of kids who kill: the boys who have (38) parents and are not poorAre their parents to blame when these kids become (39)
Most children do fine while young enough to be (40) by loving parents, but change as adolescents subjected to peer competition and rejection, (41) in big high schools, Today it becomes hard for parents to (42) between what in a teenager’s talk, dress and taste in music and video games indicates (43) trouble and what is simply a (44) of the times. Most kids who have multiple body piercing, or play the video games are normal kids caught in a toxic (45) . Intelligent kids with good social skills can be quite skillful at hiding who they really are from their parents. They may do this to (46) punishment or to protect the parents they love from being (47) or worrieD、Anyway, how many parents are (48) of thinking the worst of their son-- (49) , that he harbors murders fantasies, or that he could (50) so far as acting them out.
A．that is
B．such as
C．for example
D．at last