关于胰岛素瘤，下列哪项不是该病的特点（）

A.低血糖经常出现在空腹或活动后

B.胰岛素释放指数增加

C.血糖降至1.67mmol／L，胰岛素则停止释放

D.禁食后多在48小时出现低血糖

E.胰高血糖素可诱发低血糖

One of your crew members falls overboard from the starboard side. You should IMMEDIATELY（）.

A.apply left rudder

B.throw the crew member a life preserver

C.begin backing your engines

D.position your vessel to windward and begin recovery