Clinic Observation of Heparin on the Ratio of Peak Systolic to Least Diastolic Flow Velocity of Umbilical Artery at the Second or Third-trimester Pregnancies是什么意思_Clinic Observation of Heparin on the Ratio of Peak Systolic to Least Diastolic Flow Velocity of Umbilical Artery at the Second or Third-trimester Pregnancies在线翻译_英语_读音_用法_例句