前置胎盘产后大出血的原因是（）。
A.胎盘植入
B.子宫下段收缩力弱
C.凝血功能障碍
D.子宫下段易撕裂
E.产后未使用缩宫素
参考答案：B, D
What did John do a. He injured his client. b. He made his client totally believe what he said. c. He made his client very angry. d. He made his client lose a fortune.
肾病综合征的最常见且较重的症状是
A．水肿
B．高血压
C．尿量减少
D．昏厥
E．疲乏无力
