If，for any reason，it is necessary to abandon ship while far out at sea，it is important that the crew members should（）.

A.separate from each other as this will increase the chances of being rescued

B.get away from the area because sharks will be attracted to the vessel

C.immediately head for the nearest land

D.remain together in the area because rescuers will start searching at the vessel's last known position

骨与关节结核为继发性病变，最常继发于（）。

A.肠结核

B.淋巴结核

C.肾结核

D.胸膜结核

E.肺结核