40.布萊頓循環就是所謂的恆定 (A)容積循環 (B)溫度循環 (C)流量循環 (D)壓力循環

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.