33. Which type of valve should be installed whenever an undesired reversal of flow is possible？
(A) Throttle valve
(B) Stop valve
(C) Check valve
(D) Relief valve

29. 增加噴射器（Air ejector）的級數可得更高的真空度，即因此最後所獲得的抽氣壓力會隨其級數 之增加而產生何種變化？ (A) 降低 (B) 提高 (C) 維持不變 (D) 視流量而定

30. Which device is used to provide a limited amount of electric power for a finite periods of time to certain loads in case of a power failure on its supply side, with no break in the flow of power to the loads？ (A) Power governor (B) Transformer (C) Solid-state power converter (D) Uninterruptible power supply

31. Which type of bearing may be lubricated by seawater in a main propulsion shafting system？ (A) Thrust bearing (B) Ball bearing (C) Crosshead bearing (D) Stern bearing

32. 船舶航行經年後，為了確定船舶單軸推力軸系之狀態，主要應檢查之項目為何？ (A) 軸系中心線彎曲度 (B) 軸系中心線平行度 (C) 軸系兩端軸的高度誤差 (D) 軸系中心線偏差度和兩端軸的同軸度

34. 泵的吸入壓力基本上不受下列何者影響？ (A) 吸入高度 (B) 泵的材質 (C) 吸入管直徑 (D) 泵的轉速

35. What is the most simple method of regulating steam flow in the steam supply to the turbine？ (A) Throttle valve control (B) By-pass control (C) Pressure regulating control (D) Enthalpy control

36. 量測油浴式艉軸軸封的艉軸軸承的磨耗量（wear down）時，專用量具應架設於何處？ (A) 前端軸封 (B) 艉端軸封 (C) 中端軸封 (D) 螺槳轂

37. 在下列何處不需與機艙主控制室裝置可靠之語音通信設備？ (A) 駕駛台 (B) 輪機員住艙 (C) 船長住艙 (D) 艏艛甲板

38. Which machinery is used to produce the electrical power？ (A) Generator (B) Air compressor (C) Steering gear (D) Winch

39. Check valves must be provided on pump suctions to prevent pumping through the standby pump to the sump. Pump isolating valves should be provided to permit underway repair of either pump. Based on these descriptions, which is the correct statement？ (A) The isolating valves must be non-return valves. (B) The check valve also needs to be positioned at the pump exit in order to improve the pumping efficiency. (C) The check valve allocated on pump suctions permits no flow from the idle pump into the sump. (D) The check valve allocated on pump suctions permits the isolation of the running and standby pumps so that the isolating valves could be ignored for the emergency operation.