— Sorry, the tickets have already been sold out.

— Really? Maybe I ________ a little earlier.[ ]

A. should come  

B. should have come

C. could have come  

D. must have come

初产妇，28岁，足月妊娠，合并风湿性心脏病，心功能Ⅱ级。检查：枕左前位，胎心率正常，无头盆不称，决定经 * * 分娩。其产程处理，下列哪项正确( )

A．产妇取平卧位休息
B．出现心衰征象时吸氧
C．第二产程鼓励产妇屏气用力
D．胎肩娩出后腹部放置沙袋并用腹带包扎固定
E．产后常规注射麦角新碱，预防产后出血