[解析]
(1)C.细节理解题.根据第一段According to a new study,teens focus on rewards and have a hard time learning to avoid punishment or consider the consequences of alternative actions.根据一项新的研究,青少年专注于奖励,很难学会避免惩罚或考虑其他行为的后果.可知青少年对奖赏的反应比惩罚好,故选C.
(2)B.推理判断题.根据倒数第二段的The first was a simple model,one that learned from rewards,and the second model added to this by also learning from the option that was not chosen.The third model was the most complete and took the full context into account,with equal weight given to punishment avoidance and reward seeking.第一个是一个简单的模式,从奖励中学习,第二种模式通过学习未被选择的选项而增加了这一点.第三种模式是最完整的,考虑到了整个背景,对避免惩罚和寻求奖励给予了同等的重视.可知这三种计算模式对情况给予了不同程度的考虑,故选B.
(3)D.词义猜测题.根据下文的 it may be useful for parents and teachers to frame things in more positive terms(对家长和老师来说,用更积极的方式来描述事情可能是有用的)和Our study suggests that teens are more receptive to rewards than they are to punishments of equal value,我们的研究表明,青少年更容易接受奖励,而不是同等价值的惩罚.可知意为"反应积极的",故选D.
(4)C.推理判断题.根据最后一段的内容可知,研究表明,青少年更容易接受奖励,而不是同等价值的惩罚.对家长和老师来说,用更积极的方式来描述事情可能是有用的.可知所以选项C"如果你提前交作业,你会得到额外的奖励"对青少年最有效,故选C.