鉴定产气荚膜梭菌时应选择哪一项试验

A．Nagler试验

B．Koch现象试验

C．串珠试验

D．肥达反应试验

E．锡克试验

When launching an open lifeboat by falls，the boathooks should be（）.

A.secured forward and aft where readily available

B.secured amidships where they will not hinder the personnel

C.used for fending off

D.used for picking up survivors in the water