11.控制直昇機之垂直飛行係透過？ (A)改變循環操作的角度 (B)改變集體變距的角度 (C)增加主旋翼片轉速 (D)增加尾旋翼片轉速

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.