Directions: Read the following text. Choose the best word
Ancient Greek philosopher Aristotle viewed laughter as "a bodily exercise precious to health." But ___1___ some claims to the contrary, laughing probably has little influence on physical fitness. Laughter does ___2___ short-term changes in the function of the heart and its blood vessels, ___3___ heart rate and oxygen consumption. But because hard laughter is difficult to ___4___, a good laugh is unlikely to have ___5___ benefits the way, say, walking or jogging does.
___6___ instead of straining muscles to build them, as exercise does, laughter apparently accomplishes the ___7___ . Studies dating back to the 1930s indicate that laughter ___8___ muscles, decreasing muscle tone for up to 45 minutes after the laugh dies down.
Such bodily reaction might conceivably help ___9___ the effects of psychological stress. Anyway, the act of laughing probably does produce other types of ___10___ feedback that improve an individual's emotional state. ___11___ one classical theory of emotion, our feelings are partially rooted ___12___ physical reactions. It was argued at the end of the 19th century that humans do not cry ___13___ they are sad but they become sad when the tears begin to flow.
Although sadness also ___14___ tears, evidence suggests that emotions can flow ___15___ muscular responses. In an experiment published in 1988, social psychologist Fritz Strack of the University of Wurzburg in Germany asked volunteers to ___16___ a pen either with their teeth - thereby creating an artificial smile - or with their lips, which would produce a(n) ___17___ expression. Those forced to exercise their smiling muscles ___18___ more enthusiastically to funny cartoons than did those whose mouths were contracted in a frown, ___19___ that expressions may influence emotions rather than just the other way around. ___20___ , the physical act of laughter could improve mood.
解析accomplishes the opposite=达到相反的效果。exercise strains muscles to build them，而 laughter 则 relaxes muscles，二者相反。impossible、average、expected 均不能构成「锻炼收紧/笑放松」的对比义。
8.
A) hardens
B) weakens
C) tightens
D) relaxes
答案 D
解析decreasing muscle tone 是 relaxing muscles 的表现。笑使肌肉放松——拉伸减小——持续达45分钟。relaxes 与 decrease muscle tone 同向呼应。hardens（变硬）、tightens（变紧）、weakens（变弱）与「降低肌肉张力」矛盾。
9.
A) aggravate
B) generate
C) moderate
D) enhance
答案 C
解析help ___ the effects of psychological stress。笑放松肌肉，应有助于缓解而非加重心理压力效果。moderate=使缓和。aggravate（加重）语义反向，generate（产生）和 enhance（增强）均与 help+stress effects 不合理。
10.
A) physical
B) mental
C) subconscious
D) internal
答案 A
解析上文讨论身体反应（bodily reaction、physical fitness），此处 continued same line——产生其他类型的身体反馈，改善情绪状态。physical feedback 与 bodily reaction 呼应。mental/subconscious/internal 与上下文的身体反应链条不连贯。
11.
A) Except for
B) According to
C) Due to
D) As for
答案 B
解析引出一经典情绪理论的内容。According to one classical theory=根据某一经典理论。Except for（除…外）、Due to（由于）、As for（至于）均不能与 theory 搭配来引出其内容。
12.
A) with
B) on
C) in
D) at
答案 C
解析be rooted in=根植于，固定搭配。our feelings are partially rooted in physical reactions（我们的情感部分根植于身体反应）。with、on、at 均不与 rooted 构成此固定搭配。be rooted in sth 不可替换。
13.
A) unless
B) until
C) if
D) because
答案 D
解析do not cry ___ they are sad but they become sad when the tears begin to flow：不是「因」伤心而哭，而是「当」流泪时才变得伤心。because 表原因，not...because=并非因…而与 but 后的 when 形成对比。
14.
A) exhausts
B) follows
C) precedes
D) suppresses
答案 C
解析Although 让步：虽然悲伤确实先于泪水(precedes tears=先于眼泪发生)，但证据显示情绪也能从肌肉反应中产生。precedes 承接旧观点的先后顺序，与后面 flow from muscular responses 的新结论构成让步转折。
15.
A) into
B) from
C) towards
D) beyond
答案 B
解析flow from=源于/来自。emotions can flow from muscular responses（情绪可由肌肉反应而产生）。与上文「先流泪再变悲伤」的反向因果关系一致。flow into/towards/beyond 方向均反。
16.
A) fetch
B) bite
C) pick
D) hold
答案 D
解析hold a pen either with their teeth or with their lips=用牙或用嘴唇含/叼一支笔。hold 为主体动作动词。fetch（取来）、bite（咬）、pick（捡）均不如 hold 能概括两种含笔方式。
解析reacted more enthusiastically to funny cartoons=对搞笑漫画反应更热烈。react 与 to 搭配，描述实验参与者对刺激的反应。adapted to（适应）、catered to（迎合）、turned to（转向）均不合此处「对漫画反应更热烈」的语义。