妊娠合并心脏病孕产妇的主要并发症是
A．出血
B．感染
C．强心甙类药物中毒
D．心力衰竭
E．便秘
参考答案：D
Only when _____ possible to settle the problem. [ ]
A. does the chief editor come will it be
B. the chief editor comes will it be
C. has the chief editor come it will be
D. the chief editor comes it will be
用以说明某一事物内部各组成部分所占的比重或分布的指标是______。
A．相对比 B．发病率C．构成比 D．死亡率
