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 1930‘s 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 würzburg 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 enthusiastically to funny catoons than did those whose months 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.
1.[A]among [B]except [C]despite [D]like
2.[A]reflect [B]demand [C]indicate [D]produce
3.[A]stabilizing [B]boosting [C]impairing [D]determining
4.[A]transmit [B]sustain [C]evaluate [D]observe
5.[A]measurable [B]manageable [C]affordable [D]renewable
6.[A]In turn [B]In fact [C]In addition [D]In brief
7.[A]opposite [B]impossible [C]average [D]expected
8.[A]hardens [B]weakens [C]tightens [D]relaxes
9.[A]aggravate [B]generate [C]moderate [D]enhance
10.[A]physical [B]mental [C]subconscious [D]internal
11.[A]Except for [B]According to [C]Due to [D]As for
12.[A]with [B]on [C]in [D]at
13.[A]unless [B]until [C]if [D]because
14.[A]exhausts [B]follows [C]precedes [D]suppresses
15.[A]into [B]from [C]towards [D]beyond
16.[A]fetch [B]bite [C]pick [D]hold
17.[A]disappointed [B]excited [C]joyful [D]indifferent
18.[A]adapted [B]catered [C]turned [D]reacted
19.[A]suggesting [B]requiring [C]mentioning [D]supposing
20.[A]Eventually [B]Consequently [C]Similarly [D]Conversely
答案： C D B B A B A D C A B C D C B D A C A C