锰矿石筛分工序污染属于()
A.气溶胶
B.蒸气
C.烟
D.粉尘
E.雾
参考答案:D
按照我国《化妆品卫生规范》的规定,测定化妆品真菌和酵母菌的培养温度和培养时间分别为()
A.28℃,24小时±2小时
B.28℃,48小时±2小时
C.28℃,72小时±2小时
D.37℃,24小时±2小时
E.37℃,24小时±2小时
—How about visiting the museum?
—Good idea. But first we should find out ______ it is open. [ ]
A. how
B. whether
C. what
D. which