求翻译：（3）作业目的不同。 保养通常是降低零件磨损速度，预防故障发生，延长专用车使用寿命；而修理通常维修出现故障或失去工作能力的机件、总成，恢复油罐车良好的技术状况、工作能力，延长使用寿命。是什么意思？

(3) job purpose is different. Maintenance is usually reduced speed parts wear, failure prevention, extend the life special vehicles and repairs are usually maintenance failure or loss of working capacity of machine parts, assemblies, recovery truck in good technical condition, capability, extended service life.