关于芬太尼、舒芬太尼、阿芬太尼和瑞芬太尼的作用特点。下列哪些是正确的（）

A.舒芬太尼镇痛作用强，约为芬太尼的5～10倍

B.阿芬太尼镇痛作用弱，但起效快，维持时间短

C.瑞芬太尼是目前作用时间最短的麻醉性镇痛药，可控性强，适用于短时麻醉或镇痛

D.芬太尼静脉注射速度过快可致胸壁肌强直和心动过缓

E.支气管哮喘和重症肌无力患者禁用芬太尼

According to the Standard of Practice Handbook, a supervisor establishing procedures to eliminate conflicts of interest relating to personal trading would least likely recommend requiring:（）

A. a ban on employee investments.

B. disclosures of beneficial ownerships.

C. duplicate confirmations of employee transactions.