491.Do not print on the back of the title page.

A. 如果超过 50%的污染物造成孔堵塞,则要清理显示组件背面的孔。

B. 如果污染物造成孔堵塞超过 50%,就要清洁显示组件后面的孔。

C. 如果 50%的孔被污染物堵塞,则要清理显示组件底部的孔。

A. 拆下活门旁边的泵。

B. 拆下位于泵上的活门。

C. 拆下泵旁边的活门。

A. 描述飞机燃油系统时,应说明交替供油和燃油运输(如适用)。

B. 描述飞机燃油系统时,应提供交输供油和燃油传输(如适用)相关描述。

C. 描述飞机燃油系统时,应说明交叉供油和燃油传递(如适用)。

A. On the front of the phone,there's a screen,and you can touch the home button.

B. The screen of the phone is on the panel,and you can touch the home button.

C. The front panel of the phone has a touchscreen and a home button.

A. State structure of airframe,wings and tail.

B. Present structure of airframe,wings and empennage.

C. Describe structure of fuselage,wings,and empennage.

A. If the rush air turbine has been extracted.

B. If the Ram Air Turbine (RAT) is retracted.

C. If the pushed air turbin has been extended.

A. The purpose of radar is to obtain,process and display image information.

B. Grasping,processing and displaying grafic information is the function of radom.

C. The purpose of radar is to transmit,process and caculate image information.

A. The Check List may be designed by "Challenge" and "Response" headings or by "Item" and "Condition" headings for two pilot airplanes or for single pilot Airplanes.

B. The Check List for the pilot may be set by "Challenge" and "Response" headings for two airplanes or by "Item" and "Condition" headings for single Airplane.

C. For two pilot airplanes,"Challenge" and "Response" headings may be used on the Check List.For single pilot Airplanes,"Item" and "Condition" headings may be used.

A. PI 上显示完成数据复制所需的剩余时间。

B. PI 显示的是复制数据所需要的时间。

C. PI 上显示剩余时间以便完成数据的复制。

A. 隔离引起故障的部分。

B. 隔离部件产生了故障。

C. 引起故障的部分已经被隔离。