1. [单选题]互见中，一艘从事疏浚作业操限船与另一艘清除水雷作业的操限船相遇致有构成碰撞危险，则________。
A. 清除水雷作业的操限船为让路船
B. 从事疏浚作业的操限船为让路船
C. 两船均应运用良好的船艺采取行动以避免碰撞
D. 两船均无须采取行动
2. [单选题]If the flame from combustion in the cylinder of a four-stroke engine past the piston into the space below, the accumulation of flammable mixture would be ignited, thus resulting in _____.
A. the crankcase explosion
B. lifting of the cylinder safety valve
C. a scavenge fire
D. opening of the manhole
