三、船舶機械長期運轉將使零件表面附有不同程度之油污、積碳與鐵鏽，試敘述船上常用之清洗種類及其工作方式。（25 分）

四、請將下列英文翻譯成中文：（15 分） The piston reciprocates in the cylinder between two fixed positions called the top dead center(TDC)-the position of the piston when it forms the smallest volume in the cylinder, and the bottom dead center(BDC)-the position of the piston when it forms the largest volume in the cylinder.