Section I: Use of English

Directions: Read the following text. Choose the best word(s) for each numbered blank and mark A, B, C or D on the ANSWER SHEET. (10 points)

Though not biologically related, friends are as “related” as fourth cousins, sharing about 1% of genes. That is [1] a study, published from the University of California and Yale University in the Proceedings of the National Academy of Sciences, has [2].

The study is a genome-wide analysis conducted [3] 1,932 unique subjects which [4] pairs of unrelated friends and unrelated strangers. The same people were used in both [5].

While 1% may seem [6], it is not so to a geneticist. As James Fowler, professor of medical genetics at UC San Diego, says, “Most people do not even [7] their fourth cousins but somehow manage to select as friends the people who [8] our kin.”

The study [9] found that the genes for smell were something shared in friends but not genes for immunity. Why this similarity exists in smell genes is difficult to explain, for now. [10], as the team suggests, it draws us to similar environments but there is more [11] it. There could be many mechanisms working together that [12] us in choosing genetically similar friends [13] “functional kinship” of being friends with [14]!

One of the remarkable findings of the study was that the similar genes seem to be evolving [15] than other genes. Studying this could help [16] why human evolution picked pace in the last 30,000 years, with social environment being a major [17] factor.

The findings do not simply explain people’s [18] to befriend those of similar [19] backgrounds, say the researchers. Though all the subjects were drawn from a population of European extraction, care was taken to [20] that all subjects, friends and strangers, were taken from the same population.

[A]when

[B]why

[C]how

[D]what

[A]defended

[B]concluded

[C]withdrawn

[D]advised

[A]for

[B]with

[C]on

[D]by

[A]compared

[B]sought

[C]separated

[D]connected

[A]tests

[B]objects

[C]samples

[D]examples

[A]insignificant

[B]unexpected

[C]unreliable

[D]incredible

[A]visit

[B]miss

[C]seek

[D]know

[A]resemble

[B]influence

[C]favor

[D]surpass

[A]again

[B]also

[C]instead

[D]thus

10.

[A]Meanwhile

[B]Furthermore

[C]Likewise

[D]Perhaps

11.

[A]about

[B]to

[C]from

[D]like

12.

[A]drive

[B]observe

[C]confuse

[D]limit

13.

[A]according to

[B]rather than

[C]regardless of

[D]along with

14.

[A]chances

[B]responses

[C]missions

[D]benefits

15.

[A]later

[B]slower

[C]faster

[D]earlier

16.

[A]forecast

[B]remember

[C]understand

[D]express

17.

[A]unpredictable

[B]contributory

[C]controllable

[D]disruptive

18.

[A]endeavor

[B]decision

[C]arrangement

[D]tendency

19.

[A]political

[B]religious

[C]ethnic

[D]economic

20.

[A]see

[B]show

[C]prove

[D]tell

### Answers & Explanations (答案与深度解析)

核心逻辑解析

1. [D] what (所...的事物)。解析：句意为“这就是一项研究**所（what）**得出的结论”。that is 后接表语从句，what 在从句中作 concluded 的宾语。when, why, how 都不能作宾语。

2. [B] concluded (得出结论)。解析：搭配“a study has concluded（一项研究得出了结论）”。defended(辩护), withdrawn(撤回), advised(建议)均不符合语境。

3. [C] on (在...上)。解析：固定搭配 conduct an analysis on sb/sth（对某人/某物进行分析）。这项全基因组分析是在1932名受试者身上进行的。

4. [A] compared (比较)。解析：which 引导定语从句修饰 analysis，这项分析“比较了（compared）”几对无血缘关系的朋友和陌生人。sought(寻找), separated(分离), connected(连接)。

5. [C] samples (样本)。解析：根据科学实验语境，这些人被用作朋友和陌生人的两组“样本（samples）”。tests(测试), objects(物体), examples(例子)。

6. [A] insignificant (微不足道的)。解析：1%（的重合度）看起来可能“微不足道（insignificant）”，但对遗传学家来说并非如此。上下文构成转折对照。unexpected(意外的), unreliable(不可靠的), incredible(难以置信的)。

7. [D] know (认识/知道)。解析：大多数人甚至不“认识（know）”他们的第四代表亲。visit(拜访), miss(想念), seek(寻找)。

8. [A] resemble (像/类似于)。解析：虽然不认识第四代表亲，但却能选择“像（resemble）”我们亲属的人作为朋友。这呼应了首句“朋友就像第四代表亲一样亲近”。influence(影响), favor(偏爱), surpass(超过)。

9. [B] also (也)。解析：第一段讲了基因重合的发现，第四段继续列举其他发现：该研究“也/还（also）”发现了嗅觉基因的相似性。again(再次), instead(相反), thus(因此)。

10. [D] Perhaps (也许)。解析：上一句刚说原因目前“很难解释”，紧接着的推理自然是一种猜测：“也许（Perhaps）”它把我们吸引到相似的环境中...。Meanwhile(同时), Furthermore(此外), Likewise(同样地)。

11. [B] to (到/对于)。解析：固定搭配 there is more to it（事情远不止如此/里面大有文章）。

12. [A] drive (驱动/驱使)。解析：可能有许多机制共同起作用，来“驱使（drive）”我们选择基因相似的朋友。observe(观察), confuse(迷惑), limit(限制)。

13. [B] rather than (而不是)。解析：驱使我们选择基因相似的朋友，为的是与之带来“功能性亲缘关系”，而“不仅仅是（rather than）”朋友之间的互惠互利。此处存在深层基因机制与表面朋友利益的对比。according to(根据), regardless of(不管), along with(连同)。

14. [D] benefits (益处/好处)。解析：作为朋友带来的“好处/利益（benefits）”。chances(机会), responses(反应), missions(使命)。

15. [C] faster (更快)。解析：这几段讲这些相似的基因是如何被筛选和保留的。非凡的发现是：相似的基因似乎比其他基因进化得“更快（faster）”。

16. [C] understand (理解)。解析：研究这一点有助于“理解（understand）”为什么人类进化在过去3万年里加快了步伐。forecast(预测), remember(记得), express(表达)。

17. [B] contributory (促成的/起作用的)。解析：社会环境是一个主要的“促成（contributory）”因素（加速了人类进化）。unpredictable(不可预测的), controllable(可控的), disruptive(破坏性的)。

18. [D] tendency (倾向)。解析：搭配 people's tendency to do sth（人们做某事的倾向）。研究结果并不仅仅是为了解释人们和某些人交朋友的倾向。endeavor(努力), decision(决定), arrangement(安排)。

19. [C] ethnic (种族的/民族的)。解析：下一句提到了“欧洲血统（European extraction）”，因此这里是指相似的“种族（ethnic）”背景。political(政治的), religious(宗教的), economic(经济的)。

20. [A] see (确保)。解析：固定搭配 see (to it) that...（务必做到/小心确保...）。care was taken to see that (采取了小心措施以确保) 所有受试者都来自同一个族群。show(展示), prove(证明), tell(告诉)。

考研核心句型与高频词汇

核心短语：
 • conduct an analysis on (对...进行分析) 
 • manage to do sth (设法做到某事) 
 • there is more to it (事情远不止如此) 
 • pick (up) pace (加快步伐/加速) 
 • see (to it) that (确保/务必做到...) 

长难句剖析：
"There could be many mechanisms working together that drive us in choosing genetically similar friends rather than “functional kinship” of being friends with benefits!"
 【解析】这是一个包含定语从句的复杂句。主干是 There could be many mechanisms (可能有许多机制)；working together 是现在分词短语作后置定语修饰 mechanisms；that 引导的定语从句进一步修饰 mechanisms，说明这些机制的作用是 drive us in choosing...（驱使我们去选择...）。rather than 连接了两个并列但对比的概念。 