Scientists ______that bacteria through microscopes for many years．
A. studied
B. have studied
C. had studied
D. have seen studied
关于颗粒剂的特点叙述错误的是( )
A. 剂量较小，服用方便
B. 吸收、奏效较快
C. 适于工业生产，产品质量稳定
D. 可以包衣制成各种缓释制剂
E. 包装不严，易吸湿结块
油性软膏基质中加入羊毛脂的作用是 ( )
A. 提高软膏中药物的渗透性
B. 防止基质氧化、酸败
C. 增加药物的溶解度
D. 提高药物的稳定性
E. 减少药物的刺激性
Continuous short buzzes on the telephone indicate that the line is busy after you dial the telephone number.
A. open
B. out of order
C. disengaged
D. in use
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