资料题：According to the passage ,（　）American children are known to have been killed by family members each year。

Children who are often spanked (打) learn that it is acceptable for the strong to use force against the weak.The concept that"Might makes right" is regularly reinforced.They have an increased likelihood of becoming more aggressive towards their siblings, their fellow students,and (later in life) against their spouses and their own children.Violence as a way of behaving is a learned response.Spanking a child will stop the child from misbehaving for the moment.But studies have shown that the child's compliance will only last for a short time; corporal punishment actually increases the child's non-compliant behavior in the future."The best way to get children to behave acceptably nowadays is to listen to them, understand them, and impose limits on their conduct firmly but reasonably."Because a spanking works for a while, the parent often repeats the spanking whenever the child misbehaves.Corporal punishment may then become a standard response to any misbehavior.This can lead to increasingly frequent and harsher spanking which can exceed the"reasonable force" threshold and become abuse.According to the Institute for the Prevention of Child Abuse,"85% of all cases of physical abuse result from some form of over-discipline through the use of corporal punishment".Each year about 44 Canadian children are known to have been killed by family members; 35 of them by parents.The figure for the United States is probably about 10 times higher.