A.主動脈 B.肺靜脈 C.下腔靜脈 D.臍靜脈 E.臍動脈
A.胎兒腸蠕動減弱 B.胎兒交感神經(jīng)興奮 C.胎兒迷走神經(jīng)興奮 D.胎兒呼吸運(yùn)動減弱 E.胎兒肛門括約肌緊縮