Chemistshavebeenstud的精选

问题详情：Reading.Chemistshavebeenstudyingwhypeoplecry.Theysaythebodyproducestwokindsoftears.Onekindcleansouttheeyeifitgetsdirtinit.Butwhenpeoplecrybecauseoftheirfeelings,thesetearshavepoisonouschemical...