Peoplelaughandpeoplecry．Butitisthoughtthatemotionssuchasanger，grieforjoy，typicallymakeAmericansfeeluncomfortableandembarrassed．Theshedderoftears（落泪者）islikelytoapologize，evenwhenagreattragedywasthecause．Theobserveroftearsislikelytodoeverythingpossibletoputanendtotheemotionaltears．Butjudgingfromrecentstudiesofcryingbehavior，boththoseresponsestotearsareofteninappropriateandmayevenbecounterproductive（适得其反）．

Humansaretheonlyanimalsclearlyknowntoshedemotionaltears．Sinceevolutionhasgivenrisetofewpurposelessphysiologicalresponses，itislogicaltoassumethatcryinghasoneormorefunctionsthatincreasesurvival．

Althoughsomeobservershavesuggestedthatcryingisawaytoaskforassistanceformothers（asacryingbabymightfromitsmother），thesheddingoftearsishardlynecessarytogethelp．Vo-cal（出声的）crieswouldhavebeenquiteenough，morelikelythantearstogainattention．So，itappearsthattheremustbesomethingspecialabouttearsthemselves．

Indeed，thenewstudiessuggestthatemotionaltearsmayplayadirectroleineasingstress．UniversityofMinnesotaresearcherswhoarestudyingthechemicalcompositionoftearshaverecentlyseparatedtwoimportantchemicalsfromemotionaltears．Bothchemicalsarefoundonlyintearsthatareshedinresponsetoemotion．Tearsshedbecauseofexposuretocutonionwouldcontainnosuchsubstance．

Otherresearchersarelookingintotheusefulnessoftearsasameansofdiagnosinghumanillsandmonitoringdrugs．AtTulaneUniversity'sTeatAnalysisLaboratoryDr．PeterKastlandhiscolleaguesreportthattheycanusetearstodetectdrugabuse，tostudythecausesof"dryeye"syndrome（综合症）andtheeffectsofeyesurgery，andperhapseventomeasureexposuretoenvironmentalpollutants．

64．Whatdoesthephrase"boththoseresponses"inParagraph1referto？___

A．Cryingoutofsorrowandsheddingtearsforhappiness．

B．Theembarrassmentandunpleasantfeelingsoftheobservers．

C．Linkingillnesswithcryingandfindingthechemicalcompositionoftears．

D．Thetearshedder'sapologyandtheobserver'sefforttostopthecrying．

65．Itisknow