缓解支气管哮喘急性发作的首选治疗方法为（）
A.吸入短效β受体激动剂
B.吸入色甘酸钠
C.氨茶碱静脉注射
D.口服抗组胺药
E.静滴抗生素
参考答案：A
Miss Jones _______ music at Bardon School for five years when she was abroad and now
she is an actress.[ ]
A. taught
B. has taught
C. had taught
D. has been teaching
亚硫酸钠在显影液中的作用是
A．促进显影液还原作用
B．稳定显影液的性能并防止污染
C．提高显影液pH值
D．促进乳剂膜膨胀，加速显影
E．抑制灰雾的产生
