[解析]
(1)C.段落大意题.根据第二段的In a new study,88 volunteers how much time they spent on Facebook and the types of Facebook posts and comments that they made.In addition,they answered questions about their feelings and state of mind.They also offered saliva.Researchers tested it for cortisol.(在一 项新的研究中,88名志愿者花了多少时间在Facebook上,以及他们在Facebook上发表的帖子和评论的类型.此外,他们还回答关于他们感受和精神状态的问题.他们还提供唾液.研究人员测试他们的皮质醇).可知,本段主要介绍了研究的内容.A.research proposes研究建议;B.research methods研究方法;C.research contents研究内容;D.research results研究结果.故选C项.
(2)B.推理判断题.根据第三段的 On the other hand,youths who gave lots of "likes" and supportive comments on Facebook had lower cortisol levels. "The more social support you give to others,the lower your stress hormone levels will be," says Lupien.(另一方面 ,在Facebook上给很多"赞'和支持性评论的年轻人的皮质醇水平较低.平说:"你给与他人的支持越多,你的压力荷尔蒙水平就会越低)可推测,如果我们想压力更少,可以多给别人积极的评论.B.Give more positive comments to others.(给别人更多积极的评价)符合以上说法,故选B项.
(3)D.作者态度题.根据第四段的"This research decidedly combines the social science approach and the medical science approach on an important question in our social﹣media age," says Wenhong Chen(陈文红说: "这项研究明确地将社会科学发放和医学方法结合起来,来研究我们这个社交媒体时代的一个重要问题")和"It's ready pleasantly new to see Lupien's team study cortisol levels﹣along with questionnaire data. " ("看到卢平团队研究皮质醇水平和问卷调查数据,我们已经准备好迎接新的惊喜.")可推测,陈文红对卢平团队的研究持支持态度.A.Cautious.谨慎的;B.Critical.批判的;C.Doubtful.怀疑的;D.Approving.支持的.故选D项.
(4)D.细节理解题.根据最后一段的 Also,she recommends that people who use social media heavily should find time to take active walks,to run or to do other activities.Cortisol increases a person's energy. "The best way to reduce stress hormones is to use the energy," she says.(卢平建议频繁使用社交媒体的人应该找时间进行积极的散步、跑步或者其他活动.皮质醇增加一个人的能量.减少压力荷尔蒙的最好方法是利用这些能量.)可知,体育锻炼可以消耗能量,从而降低皮质醇.D.Doing physical exercise helps reduce the levels of cortisol.(做体育锻炼帮助减少皮质醇的量)符合以上说法,故选D项.