英语翻译Belowisaselectionfromapopularsciencebook.（标题1）Ifbloodisred,whyareveins（静脉）blue?Actually,veinsarenotblueatall.Theyaremoreofaclear,yellowishcolor.Althoughbloodlooksredwhenit’soutsidethebody,

Question

英语翻译
Below is a selection from a popular science book.
（标题1）If blood is red,why are veins（静脉）blue?
Actually,veins are not blue at all.They are more of a clear,yellowish color.Although blood looks red when it’s outside the body,when it’s sitting in a vein near the surface of the skin,it’s more of a dark reddish purple color.At the right depth,these blood-filled veins reflect less red light than the surrounding skin,making them look blue by comparison.
（标题2）Which works harder,your heart or your brain?
That kind of depends on whether you’re busy thinking or busy exercising.Your heart works up to three times harder during exercise,and shifts enough blood over a lifetime to fill a supertanker.But,in the long run,your brain probably tips it,because even when you’re sitting still your brain is using twice as much energy as your heart,and it takes four to five times as much blood to feed it.
看不懂,而且本人翻译的也不好,

Answer 1

以下内容选自一本科普读物.
I.既然血液是红色的,为什么静脉是蓝色的呢?
事实上,静脉并非蓝色的,而是更接近淡黄色.尽管在人体外的血液看起来是红的,但在皮肤浅表的静脉里,它更接近紫色,但又略显暗红.在皮肤深层,这些充血的静脉反射出的红色光线稍逊于周边的皮肤,反衬之下就呈蓝色了.
II.哪个工作更忙,心脏还是大脑?
这要看你是忙于思考还是忙于运动.在运动时,心脏的工作强度足足是大脑的三倍,在人的一生中传输的血液足以装满一个超级油箱.但是,从长期来看,大脑很可能更忙,因为即使人坐着不动,大脑消耗的能量仍然是心脏消耗的两倍,因此它也需要四到五倍的血液来供应.