A、 This is the maximum portion of flammable vapors in air. If the portion is bigger, when an ignition source touched the gas, it would cause the fire to be diffused.
B、 This is the minimum volume of flammable vapors. If the volume is lower, when the gas contacted with an ignition source, the fire would not come out.
C、 This is the minimum density of flammable vapors in air. If the density was lower, when an ignition source touched the gas, it would not cause the spread of flame.
答案：C
A、 This is the maximum portion of flammable vapors in air. If the portion is bigger, when an ignition source touched the gas, it would cause the fire to be diffused.
B、 This is the minimum volume of flammable vapors. If the volume is lower, when the gas contacted with an ignition source, the fire would not come out.
C、 This is the minimum density of flammable vapors in air. If the density was lower, when an ignition source touched the gas, it would not cause the spread of flame.
答案：C
A. Please stand near the moving surfaces.
B. Never stay near the removed surfaces.
C. Do not stay near the moving surfaces.
A. Distances shown are based on weak wind.
B. Distances shown are developed with no wind.
C. Distances shown are on the basis of gentle wind.
解析：首先，这道题考察的是对风速对距离的影响的理解。在航空领域，风速对飞行距离有很大的影响。如果风速为零，那么所显示的距离就是在没有风的情况下测量的距离，也就是答案B所说的"Distances shown are developed with no wind"。
举个例子来帮助理解，想象一架飞机在没有风的情况下从A点飞往B点，飞行距离是100公里。但如果有风的话，飞机在风的影响下可能需要调整飞行路线，实际飞行距离可能会有所变化。因此，为了准确测量飞行距离，通常会以零风速为基准来显示距离。
A. The operation procedure requires that the maintenance behavior be logically executable.
B. The logical maintenance steps or operating procedures constitute the maintenance procedures.
C. Break down maintenance activities into logical steps or operations as required by procedures.
A. "EMERGENCY EXIT" placard at exit hatch over Left wing is illegal.
B. "EMERGENCY EXIT" placard at exit hatch over Left wing is not legible.
C. "EMERGENCY EXIT" placard at exit hatch over Left wing is missing.
A. Licensed personnel appropriately finish the requirements of all other maintenance on airplane.
B. All other maintenance required on airplane should be done by the personnel who have the corresponding license.
C. All other maintenance requires that the properly licensed personnel should be on airplane.
A. The removal/installation portion shall state clearly the sequence of steps required to remove and reinstall a component or unit. This portion shall also state precautions to be obeyed.
B. The removal/installation portion shall state clearly the sequence of steps required to remove and reinstall a component or unit. This portion shalln’t include precautions to be obeyed.
C. The removal/installation portion shall hardly state the sequence of steps required to move and reinstall a component or unit. This portion shall also include precautions to be watched.
A. When the light goes off, set the switch to NORMAL.
B. When the light is illuminated, move the switch to NORMAL.
C. When the light is extinguished, move the switch to NORMAL.
解析：这道题考察的是根据指示操作开关的能力。正确答案是B: 当灯亮起时，将开关设置为正常。这句话的意思是当灯被点亮时，你需要把开关设置为正常。选项A中的“goes off”表示灯熄灭，与题目中的“comes on”相反，所以不是正确答案。选项C中的“extinguished”也表示灯熄灭，与题目中的“illuminated”相反，所以也不是正确答案。
举个生动的例子来帮助理解：想象你在一个房间里，有一个开关控制着房间里的灯。当你看到灯亮起时，你需要把开关设置为NORMAL，这样灯就会保持亮着。所以正确答案是B。
A. The units used by pilots are the most valuable.
B. The units used are those which are the most expensive for pilots.
C. The units are the most useful for the pilots.
A. If there is not a conflict between the two indicators, repeat the test.
B. If the two indications are different, do the test again.
C. Do the test again unless the two indications are different.
A. Use white paper with good strength characteristics and enough weight and substance to eliminate excessive print leakage when printing on both sides.
B. Use good white paper with high strength quality and of adequate weight to delete excessive show-through when printed on both sides.
C. Use white paper with good strength and of sufficient weight and substance to prevent overmuch ink show-through the paper when printed on both sides.
