Center of gravity is the point at which an airplane would balance if suspended. Its distance from the reference datum is found by dividing the total moment by the total weight of the airplane.

A. 只对表面申请很轻的压力。

B. 只传导很轻的压力到表面。

C. 只对表面施加很轻的压力。

A. Metal objects attract magnetic interference.

B. Magnetic interference can occur to the metal objects.

C. Metal objects can cause magnetic interference.

A. Turn the handle of the door until the lower gate is lifted.

B. For lowering the upper door, door handle should be turned.

C. The lever of door should be turned until the lower door opens.

A. 如果发现铜颗粒, 在发现之日起的30天内重复执行整个程序(机轮不承重)。

B. 如果发现金属碎屑，从即日起在30天内完成整个修理程序（机轮承重）。

C. 如果发现琥珀色指示参数，针对发现的数据在30天内重复所有程序（机轮离地）。

A. 如果你得到了一个不需要的移动，做系统测试。

B. 对于非指令运动，需要使用该系统进行测试。

C. 出现非指令运动时，对系统进行测试。

A. 齿轮箱是一个包含齿轮系和轴的箱体。

B. 齿轮箱包含了齿轮火车和曲轴。

C. 有一类齿轮箱包含了齿轮组和轴。

A. 对于利用空气作为防冰介质的涡轮类动力装置，发动机防冰功能包含在空气系统中。

B. 因为涡轮类型动力组合使用气体作为防止积冰的渠道，发动机防积冰设备被储存在空气系统下。

C. 因为涡轮动力装置将空气用来防止积冰，发动机防冰包含在通风系统中。

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. 给化合物的两部分称重。

B. 提取出复合物的两部分。

C. 分离出混合物的两部分。

A. The manufacturer shall prepare all text in either one or two columns with justification at his own discretion , but, two columns are preferable for readability.

B. Manufacturers shall prepare all text both in one and two columns separately; however, two columns are better for reading.

C. According to the manufacturer＇ explanations, all text shall be prepared in one or two columns; however, two columns have better visual effect.