21.鉚釘孔之承載面積是何者的函數? (A)鉚釘的材質 (B)單一平面上鉚釘孔的數目 (C)鉚釘孔的直徑乘以材料厚度 (D)鉚釘型式

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.