—Why didn’t you go to the cinema with us yesterday evening?

—I________for my uncle from Beijing at the station.

A．was waiting

B．am waiting

C．will wait

D．waited

患者，男性，32岁，患急性扁桃体炎。医嘱青霉素过敏试验阴性后，肌内注射160万U青霉素。

护士在青霉素过敏试验前才配置试验液的目的是

A．防止挥发失效
B．保持药液无菌
C．防止药物过敏
D．减少青霉烯酸的产生
E．减少青霉噻唑蛋白的产生