48.星型發動機最常使用之推力軸承型式為 (A)錐狀滾柱軸承 (B)深槽滾珠軸承 (C)雙排直列滾柱軸承 (D)雙排滾珠

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.