The difference of the mean operating time and blood loss between tow groups were not significant(P 0.05).
两组手术时间、术中出血量差异无显著性意义（P〉0.05）。
If the 50% actual operating time of aircraft engine is greater than the mean TBO in airline operation, the TBO can be prolonged. The method for estimating the prolonged life is also given.
航线使用中如有50%以上发动机实际使用寿命超过平均翻修寿命，发动机就可以延寿，给出了延寿估算方法。
If the 50% actual operating time of aircraft engine is greater than the mean TBO in airline operation, the TBO can be prolonged. The method for estimating the prolonged life is also given.
航线使用中如有50%以上发动机实际使用寿命超过平均翻修寿命，发动机就可以延寿，给出了延寿估算方法。
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