28.在 AC 發電系統，頻率與相位轉動應 (A)在並聯之前必須同步 (B)並聯之前必須不同相位 (C)並聯後沒有影響 (D)串聯後沒有影響

5. If an aircraft is operating at 40,000 ft. the pressurization ensures that (A)sea level pressure is maintained in the cabin. (B)the cabin pressure is progressively increased until the operational height is reached. (C)the cabin pressure above 10,000 ft. (D)the cabin pressure is equivalent to an altitude of less than 10,000 ft.