502、如果过滤器在异常短的时间后堵塞，将它们送到实验室进行污染分析。

986、The assembly extends through the casing assemblies and is connected to the telescopic control assembly.

985、Adjust the door operating rod until it aligns with the attachment point.

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

983、The selection of data by the handbook producer, to be included in this Section shall be governed by the conceptscontained in the preface of this Specification.

982、It is the responsibility of the airplane owner and the pilot to insure that the airplane is loaded properly.

981、Lower the antenna to get access to the cab connector.

980、使用危险品之前,遵守以下注意事项。

979、Do the procedure that follows.

978、确保襟翼位置对称。

977、Disconnect the cable from the rear side of the instrument