25.翼樑從翼根到翼尖漸縮是因為 (A)在翼根的彎曲力矩最大 (B)升力中心在靠近翼根處 (C)在翼根的剪力最大 (D)在翼根的扭力最大

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.