产褥感染的诱因不包括()
A.孕期贫血、营养不良
B.产程长,胎膜早破或失血多
C.手术产,手取胎盘
D.产程中多次 * * 检查
E.先兆子痫
参考答案:E
The key ________ the problem of traffic jams is to pay the "congestion charge" ________ by the
mayor of London. [ ]
A. to solving; introducing
B. to solve; introducing
C. to solving; introduced
D. to solve; introduced
全回流操作所需的理论塔板数为()。
A.最多
B.最少
C.不确定
D.无限多