01 【长难句】

　　The engines would have variable nozzles, which would be fully opened on take-off and landing, so that the exhaust would be slow and relatively quiet, and narrowed when the aircraft was cruising, providing the necessary speed.

　　02【句型分析】

　　本句是主从复合句。主句为The engines would have variable nozzles。其后的定语从句比较复杂，以逗号后and为切入点，得到which would be fully opened…and narrowed…，关系代词which指代先行词nozzles在从句中作主语。其中so that引导的结果状语从句so that the exhaust would be slow and relatively quiet说明(nozzles)would be fully opened on takeoff and landing情况发生时所产生的结果，句末的现在分词结构providing the necessary speed 作(nozzles)would be narrowed when the aircraft was cruising情况发生时的伴随结果。

　　03【词汇】

　　engine 引擎

　　variable 各种各样的

　　exhaust n.排气---exhausted 筋疲力尽的

　　cruise 巡航，巡游

　　04【参考译文】

　　引擎配有各种各样的尾喷管，在起飞和降落时它们会全部打开，这样喷气速度会下降，噪音也会更小;而在飞机巡航过程中，尾喷管将变小以保证必要的飞行速度。