与流脑患者密切接触后的重要预防措施是( )
A．菌苗预防注射B．隔离观察C．口服磺胺药D．注射青霉素E．开窗通风
参考答案：C
控制性降压的适应证中，不包括（）。
A.颅内血管瘤
B.中耳手术
C.麻醉期间高血压
D.PDA结扎术
E.低血容量
An investor wishes to short sell 500 shares of McDonald Corporation. The shares open lower at $14.50 and the next five transactions are $14.00, $14.00, $13.50, $14.25, and $14.50. The lowest price at which the order can be executed is:（）
A. $14.25.
B. $13.50.
C. $14.00
