During the course of a voyage，a seaman falls on the main deck and injures his ankle. The Master should submit a Report of Marine Accident，Injury or Death if the（）.

A.injured needs first aid

B.injured is incapacitated

C.injury results in loss of life only

D.injury is the result of misconduct

探索精神。科学始于好奇，（）的好奇心是科学产生和不可缺少的心理因素。

A.永无止境

B.必不可少

C.刻不容缓

D.一马当先