四肢出血，使用止血带最长不能连续超过（）
A.20分钟
B.30分钟
C.1小时
D.1.5小时
E.2小时
参考答案：C
Try not to be absent from class again for the rest of the term. You _____ too many classes. You _____ two classes just last week.
A．have missed; missed
B．missed; missed
C．had missed; have missed
D．will miss; have missed
哮喘病人围术期并发症可比呼吸系统正常的病人高（）。
A.0倍
B.1倍
C.2倍
D.3倍
E.4倍
