英语翻译
Belowisaselectionfromapopularsciencebook.
(标题1)Ifbloodisred,whyareveins(静脉)blue?
Actually,veinsarenotblueatall.Theyaremoreofaclear,yellowishcolor.Althoughbloodlooksredwhenit’soutsidethebody,whenit’ssittinginaveinnearthesurfaceoftheskin,it’smoreofadarkreddishpurplecolor.Attherightdepth,theseblood-filledveinsreflectlessredlightthanthesurroundingskin,makingthemlookbluebycomparison.
(标题2)Whichworksharder,yourheartoryourbrain?
Thatkindofdependsonwhetheryou’rebusythinkingorbusyexercising.Yourheartworksuptothreetimesharderduringexercise,andshiftsenoughbloodoveralifetimetofillasupertanker.But,inthelongrun,yourbrainprobablytipsit,becauseevenwhenyou’resittingstillyourbrainisusingtwiceasmuchenergyasyourheart,andittakesfourtofivetimesasmuchbloodtofeedit.
看不懂,而且本人翻译的也不好,