GMP规定注射用水应于制备后几小时内使用（）
A.1小时
B.2小时
C.12小时
D.18小时
E.24小时
参考答案：C
当3＜x＜5时，|x-5|-|x-3|化简结果是______．
Nowadays, people get news around them and about the world from______media, on TV, by radio, in the newspaper or on the Internet. [ ]
A. formal
B. precious
C. various
D. normal
