24. 船舶推進軸系統中，就下圖而言(4)應為下列何者？ (A) 螺葉(blade) (B) 螺毂(boss) (C) 葉根(blade root) (D) 葉尖(blade tip)

) 5. Which situation do not need to stop engine for emergency in the following situations? (A) Moisture is separated from the lubricating oil. (B) An unusual sound has been made. (C) Heat has generated unusually from a part. (D) Smoke is issued from a bearing or any other moving part.