490. Remove the caps from the hoses

A. 直升机最常用的两类发动机是星型发动机和涡轮发动机。

B. 螺旋桨飞机最常用的两类发动机是往复式发动机和涡喷发动机。

C. 直升机最常用的两类发动机是活塞发动机和涡轮发动机。

A. Pressurization of the pneumatic crossover manifold and use of an external air source connected to the air charging valve manifold to pressurize the reservoirs for ground maintenance is the second method.

B. You can use the second method to pressurize crossover manifold and use an external air source connected to the air charging valve manifold to pressurize the reservoirs for ground maintenance.

C. The second method is that it is not necessary to pressurize the pneumatic crossover manifold but to use an external air source connected to the air charging valve manifold to pressurize the reservoirs for ground maintenance.

A. When you try to change a word, make sure that the substitute you choose doesn＇t replace the meaning of the sentence.

B. Make sure that the chosen replacement word will not vary the implication of the sentence if you replace a word.

C. When you replace a word, always make sure that the alternative you select does not change the meaning of the sentence.

A. 将飞机速度除以侧风分量来得到修正。

B. 用侧风分量除以飞机速度,得到修正值。

C. 将侧风部件和飞机分开,来得到正确的速度。

A. 三个月后给局方发送一次报告。

B. 每隔三个月给局方发送一次报告。

C. 每隔三个月给政府发送一次报告。

A. The windshields are filled in a form that requires an exact shape, but they are necessary to have a slightly larger space for the ease of adjustment.

B. The shape of the windshields has exact requirements, but for purpose of exact size, they appear slightly larger.

C. These windshields are shaped to a required exact appearance, but in order to be clipped accurately, they are a little bigger than necessary.

A. Send the results of the audit to the quality department

B. Tell the quality department about the results of the analysis.

C. Let the quality department know the results of audit

A. That portion of the system and its controls which supply heated air to the cabin. Includes items such as cooler units, oil system and control, ignition, indicating systems related to heater operation, etc., as applicable. Does not include the temperature control and indicating systems

B. That portion of the system and its controls which supply heated air to the cabin. Includes items such as heater units, fuel system and control, ignition, indicating systems related to heater operation, etc., as applicable. Does not include the temperature control and indicating systems

C. That portion of the system and its controls which supply cooling air to the cabin. Includes items such as heater units, fuel system and control, ignition, indicating systems related to heater operation, etc., as applicable. Does not include the hot control and indicating systems.

A. Those fire-resistant partitions and seals mounted on or about the power package for the purpose of isolating areas subject to fire.

B. Those fire-resistant partitions and seals mounted on or about the power package to isolating areas subject to fire.

C. Those fire-resistant partitions and seals mounted on or below the power package for the purpose of isolating areas subject to fire.

A. The menu of contents in front of each chapter will Projects covered and the numbers assigned.

B. The catalogue of texts in front of each chapter will list the items covered and the assigned numbers.

C. The table of contents in front of each chapter will list the items covered and the number assigned.