【典型例句1】：Though not biologically related, friends are as “related” as fourth cousins, sharing about 1% of genes.
【例句解析】：本句是一個簡單句，主干是friends are as “related” as fourth cousins，是一個同級比較結(jié)構(gòu)，as…as…意為“和……一樣……”。Though not biologically related是一個分詞短語做狀語的情況，包含省略，完整的句子應(yīng)該是Though friends are not biologically related(主從句的主語一致)，和主干構(gòu)成轉(zhuǎn)折關(guān)系。sharing about 1% of genes是分詞短語做結(jié)果狀語。【例句釋義】：雖然從生物學(xué)角度而言，朋友之間并沒有親屬關(guān)系，但是朋友之間的相關(guān)性卻如同和第四代的堂兄弟姐妹一樣緊密，共有大約1%的基因。

【典型例句2：】That is what a study published from the University of California and Yale University in the Proceedings of the National Academy of Sciences, has concluded.

【例句解析】：這句話的主干是That is what a study has concluded，published from the University of California and Yale University in the Proceedings of the National Academy of Sciences是后置定語修飾study，翻譯是應(yīng)當獨立成句。

【難句點撥】：這句話的難點在于誤把published作為謂語動詞，而不能理解has concluded語法作用。需要明確的是動詞的-ed形式既可以看作過去式，用做句子的謂語動詞，也可以看作過去分詞形式，做非謂語成分。而has concluded形式卻只能做謂語。
【例句釋義】：這是一項研究的結(jié)論，它發(fā)表在《美國科學(xué)院會刊》上，是來自加利福尼亞和耶魯大學(xué)的研究結(jié)果。

【典型例句3】：Most people do not even know their fourth cousins but somehow manage to select as friends the people who resemble our kin.
【例句解析】：這句話的主干是Most people do not even know their fourth cousins but somehow manage to select as friends the people，是由but并列謂語部分;who resemble our kin是定語從句修飾people。but之前是主謂賓的簡單句結(jié)構(gòu)，but之后是manage to do sth.(設(shè)法做成某事)，其中的select as friends the people who resemble our kin包含賓語后置，即原句是select the people who resemble our kin as friends，即select A as B的結(jié)構(gòu)。由于A部分有定語從句修飾，頭重腳輕，所以把整體“先行詞+定語從句”整體移到句末。

【例句釋義】：大多數(shù)人甚至并不認識他們的第四代堂兄弟姐妹，但是某種程度上，卻成功地選擇了那些像我們親戚的人們作為朋友。
【典型例句4】：The study also found that the genes for smell were something shared in friends but not genes for immunity.

【例句解析】：這句的主干是The study also found that…，that引導(dǎo)一個賓語從句。賓從中包含一個省略，完整的句子應(yīng)該是the genes for smell were something shared in friends but genes for immunity (were not something shared in friends)。
【例句釋義】：研究也表明：嗅覺基因是朋友間共有的東西，而免疫基因則不是朋友間共有的。

【典型例句5】：There could be many mechanisms working in tandem that drive us in choosing genetically similar friends rather than “functional kinship” of being friends with benefits!
【例句解析】此句的主干是There be句型，There could be many mechanisms。working in tandem是定語，修飾mechanisms;that引導(dǎo)定語從句，修飾mechanisms。
【例句釋義】：在選擇基因上相似的朋友方面，而不是選擇存在相互利益的“功能親屬”成為朋友方面，可能存在許多相互連接的機制，這些機制對我們有驅(qū)動作用。