国家根据非处方药品的安全性,将非处方药分为()?
A.OTC和R
B.一般非处方药和特殊非处方药
C.一类处方药和二类非处方药
D.甲类非处方药和乙类非处方药
参考答案:D
We were about to start out________ our friends called us up from Shanghai.
A.when
B.while
C.until
D.before
饱和溶液可能是浓溶液,也可能是稀溶液。