县级疾病预防控制机构对不明原因肺炎病例开展流行病学调查时重点了解的流行病学史包括什么（）

A、周围有无聚集性发病现象

B、有无相应的高危职业史

C、有无外出务工史

D、是否曾接触禽类或野生动物

E、有多少兄弟姐妹

The investment-banking department of the XYZ Brokerage House often has information that would be of significant use to the firm’s brokerage clients. In order to conform to CFA Institute Standards of Professional Conduct, which of the following policies should XYZ adopt According to Standard:（）

A. Ⅱ (A), Material Nonpublic Information, XYZ should encourage their investment banking clients to publicly disseminate this information. 

B. Ⅲ (B), Fair Dealing, all clients should be informed of the information at the same time. 

C. Ⅱ (A), Material Nonpublic Information, XYZ should establish physical and informational barriers within the firm to prevent the exchange of information between the investment banking and the brokerage operations.