下列气体可用启普发生器制取的是[ ]
(1)H2S (2)SO2 (3)HCl (4)Cl2
A、只有(1)
B、(1)和(4)
C、(1)(2)(4)
D、(1)和(2)
答案:A
.By using ear sonecan tell the direction____a sound comes.
A.in which
B.from which
C.with which
D.through which
直接接触药品,便于清洗、消毒灭菌的药品包装材料属于注册管理的药品包装材料产品分类中的()
A.Ⅰ类
B.Ⅱ类
C.Ⅲ类
D.Ⅳ类