母亲与婴儿的血液在胎盘发生交汇,氧气和营养物质通过脐带进入婴儿体内,而代谢废物由
%B0%FC%D3%AE%CD%B8%CA%D3%B6%FE%D5%C5%C5%C6%D1%A5%BA%CF%D7%F7%2D%A1%BE%40%31%33%37%31%30%30%37%39%36%38%38%A1%BF
%B0%FC%D3%AE%CD%B8%CA%D3%B6%FE%D5%C5%C5%C6%D1%A5%BA%CF%D7%F7%2D%A1%BE%40%31%33%37%31%30%30%37%39%36%38%38%A1%BF
%B0%FC%D3%AE%CD%B8%CA%D3%B6%FE%D5%C5%C5%C6%D1%A5%BA%CF%D7%F7%2D%A1%BE%40%31%33%37%31%30%30%37%39%36%38%38%A1%BF
%B0%FC%D3%AE%CD%B8%CA%D3%B6%FE%D5%C5%C5%C6%D1%A5%BA%CF%D7%F7%2D%A1%BE%40%31%33%37%31%30%30%37%39%36%38%38%A1%BF




