The most appropriate reason for an investor to sell a security short is the investor’s belief that, in the near future.（）

A. the security’s price will decline.

B. interest rates will decline.

C. The required rate of return on the security will decline.

与顽固性根尖周病变和窦道经久不愈可能有关的细菌为（）

A.普氏菌

B.放线菌

C.G⁺细菌

D.真杆菌

E.梭形杆菌