2.如有必要,加一个垫圈。

58、The unit pressurizes and filters the oil.

57、如果驾驶舱显示有发动机过热警告,不要给飞机加油。

56. When this occurs, 9th stage bleed air is automatically used.

55、遵守部件的拆卸程序。

54、Identify a revision to an illustration with a black vertical line in the left margin opposite the revised portion or use a pointing hand.

53、lf the ＇meaning changes, use a different construction.

52、解释如何检查它们是否正常运行,以及如何识别故障

51、词典包括一些未经批准的词,如果能把这些词归在适用的技术名称类别中,它们可以是技术名称。

50、Revisions, additions and deletions shall be identified by a vertical black line along the outside of the page opposite only that portion of the printed matter that was changed.

49、You can stow life vests in the space under the seats.