7. 哪個頻率是用作飛機 VOR 導航？ (A)1.260 兆赫 (B)104.50 兆赫 (C)112.50 兆赫 (D)122.50 兆赫

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.