1A new study published in the journal Child Development, by Eveline Crone of the University of Leiden and colleagues, suggests that the positive and negative sides of teenagers go hand in hand.
主干主语：A new study；谓语：suggests；宾语：that 引导的宾语从句（the positive and negative sides of teenagers go hand in hand）
结构主干为 A new study suggests that...。主语后接过去分词短语 published in the journal Child Development 作后置定语；两个逗号之间的 by Eveline Crone of the University of Leiden and colleagues 是插入语，补充研究者信息，阅读时可先跳过。that 引导宾语从句，从句主干为 the positive and negative sides go hand in hand。
译文莱顿大学的 Eveline Crone 及其同事在《儿童发展》期刊上发表的一项新研究表明，青少年积极的一面和消极的一面是相伴而生的。
考点过去分词短语 published in... 作后置定语，相当于定语从句 which was published in... · go hand in hand 为高频习语，意为"密切相关、相伴而生"，考研阅读常考
2The participants filled out questionnaires about how often they did things that were altruistic and positive, like sacrificing their own interests to help a friend, or rebellious and negative, like getting drunk or staying out late.
主干主语：The participants；谓语：filled out；宾语：questionnaires
结构主干为 The participants filled out questionnaires。about 后接 how often 引导的宾语从句，说明问卷内容；从句中 things 后接 that 引导的定语从句，定语从句内部由 or 连接两组并列表语 altruistic and positive 与 rebellious and negative，每组后各跟一个 like 引导的举例成分，层次较多，需理清归属。
译文参与者填写了问卷，说明他们做某些事情的频率：一类是利他、积极的事，比如牺牲自己的利益帮助朋友；另一类是叛逆、消极的事，比如酗酒或在外待到很晚。
考点how often 引导宾语从句作介词 about 的宾语，注意从句用陈述语序 · or 连接的两组 like... 举例分别对应前后两类事情，翻译时可用"一类是……另一类是……"理清结构
3Teenagers were more likely than younger children or adults to report that they did things like unselfishly helping a friend.
主干主语：Teenagers；谓语（系表）：were more likely；宾语从句：that they did things...
结构主干为 Teenagers were more likely to report that...。than younger children or adults 为比较状语，插在 be likely to 之间，容易造成割裂感；that 引导宾语从句作 report 的宾语；like unselfishly helping a friend 为介词短语作 things 的后置定语，like 后接动名词。
译文与更年幼的儿童或成年人相比，青少年更可能表示自己做过诸如无私帮助朋友之类的事情。
考点be likely to do 中插入比较级 than...，注意还原语序：more likely to report... than... · like 作介词表举例，后接动名词 helping，而非动词原形
4One idea is that teenage behavior is related to what researchers call "reward sensitivity."
主干主语：One idea；谓语（系动词）：is；表语：that 引导的表语从句
结构主干为 One idea is that...。that 引导表语从句；表语从句中 is related to 的宾语由 what 引导的名词性从句充当，what 在从句中作 call 的宾语补足语（call + 宾语 + 补语结构），即 researchers call (it) "reward sensitivity"，what 顶替了被称呼的内容。
译文一种观点认为，青少年的行为与研究者所称的"奖赏敏感性"有关。
考点what 引导名词性从句作介词 to 的宾语，what 在从句中充当成分（此处为宾语补足语），这是 what 与 that 引导从句的核心区别 · be related to 后接名词性成分，可接名词、代词或名词性从句
5Somehow, when you hit 30, the chance that something exciting and new will happen at that party just doesn't seem to outweigh the effort of getting up off the couch.
主干主语：the chance；谓语：doesn't seem to outweigh；宾语：the effort
结构句首 Somehow 为评注性状语，when you hit 30 为时间状语从句。主句主干为 the chance doesn't seem to outweigh the effort；chance 后接 that 引导的同位语从句，说明"机会"的具体内容，that 在从句中不作成分，不可省略也不可换成 which。of getting up off the couch 为介词短语作 effort 的后置定语。
译文不知怎么的，一到30岁，派对上会有新鲜刺激之事发生的可能性，似乎就抵不过从沙发上爬起来所要付出的力气了。
考点that 引导同位语从句修饰抽象名词 chance，与定语从句的区别在于 that 不作成分、从句语义完整 · hit 30 为口语化表达，意为"到了30岁"；outweigh 意为"比……更重要、超过"，是考研高频动词