对基准物质的要求是（）
A.纯度高
B.组成恒定
C.低温储存
D.性质稳定
E.具有较大的摩尔质量
参考答案：A, B, D, E
If a CFA Institute member knows that a fellow employee has violated a law, according to Standard Ⅰ (A) the member must NOT do which of the following（）
A. Report the employee violating the law to the appropriate supervisor in the firm.
B. Report the employee violating the law to the SEC.
C. Disassociate from the employee violating the law.
建设项目职业病危害卫生审查工作重点是审查
A．防护设施设计
B．卫生隐患处理
C．卫生设施费用
D．设计平面图
E．安全教育规划
