【名词&注释】
交感神经(sympathetic nerve)、氨茶碱(aminophylline)、表面张力(surface tension)、重要作用(an important role)、氧化亚氮(nitrous oxide)、多巴胺(dopamine)、尿潴留(urinary retention)、腰背痛(back pain)、麻醉药作用
[单选题]麻醉前对病人的分级,其ASA的意义为()
A. American Societyof Anesthesiologists
B. American Stomatological Association
C. American Surgical Association
D. American Standard Association
E. American Statistical Association