消风散的功用是
A．祛风散寒，活血止痛B．疏风除湿，清热养血C．祛风解表，散寒除湿D．祛风化痰，通络止痉E．祛风化痰，止痉定痛
参考答案：B
操作风险
A spark arrestor（）.
A.keeps sparks from falling into an open tank
B.secures covers on ullage openings
C.prevents sparks from getting out of an enging's exhaust system
D.grounds static electicity
