能解蛇毒的药是（）。

A．川乌

B．秦艽

C．防己

D．桑枝

E．徐长卿

On open lifeboats，the purpose of the wire stretched between the davit heads is to（）.

A.keep the movement of the davits at the same speed

B.keep the davits from slipping when they are in the stowed position

C.prevent vibration during lowering of the boat

D.support the manropes