9. 主機備俥從碼頭移船到二號浮筒. Standby main engine for shift from pier to No.2 _______. (A) quay (B) wharf (C) bureau (D) buoy

3. The layout of drain systems can often be improved by the use of automatic pumps. Condensate can be drained by gravity more readily to local receivers and then pumped back to the engine room as required. What type of operated traps is above description? (A) Mechanical trap (B) Thermostatic trap (C) Thermodynamic trap (D) Vacuum trap