If there is no contamination in the fuel sample, continue the procedure.

A. 中心句是一篇文章的第一句，也是最重要的一句。

B. 总结句是一节内容的第一句，也是最重要的一句。

C. 主题句是一段话的第一句，也是最重要的一句。

A. Handbooks shall be ready to revise in accordance with the specification.

B. In accordance with the specification, manuals should be easy to revise.

C. Handbooks have been already revised, according to the specification.

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. The Index Numbering System is described in the following paragraph.

B. The Index Numbering System is introduced in the next paragraph.

C. The Index Numbering System is compared in the later paragraph.

A. 标题页的背面应留白，以免需要改版，以及可能遗漏插入的飞机序列号和注册号。

B. 标题页的背面应保持空白，以备需要插入可能遗漏的飞机序列号和注册号。

C. 标题页的背面应有充分的内容，以免被插入遗漏的飞机序列号和注册号。

A. Utilize an oil-free solution.

B. Use a solution with oil.

C. The oil is not used that contains a solution.

A. 刹车系统阐述了如何识别故障问题以及如何处理故障。

B. 刹车系统介绍了如何判断故障问题以及如果发生故障如何处理。

C. 刹车系统解释了如何识别即将出现的问题以及如果发生故障怎么办。

A. "Towing and Taxiing" shall include procedures to be used such as ground turning techniques, use of parking brakes, connection of electrical power, etc..

B. "Towing and Taxiing" shall include procedures to be used such as ground steering techniques, use of chocks, connection of electrical power, etc..

C. "Towing and Taxiing" shall include procedures to be used such as ground turning techniques, use of brakes, connection of electrical power, etc..

A. If the error is more than 3 degrees, calibrate the glide slope.

B. If the error is more than 3 degrees, calibrate the compass.

C. If the error is more than 3 degrees, calibrate the gyroscope.

A. 绕其轴线旋转此曲柄。

B. 绕其圆心旋转此杆。

C. 绕其轴线旋转此轴。