| 1. | 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 引擎将配有大小可以调节的尾喷管:起飞和降落时会全部打开,这样喷气速度会下降、噪音也会更小;而巡航飞行过程中,尾喷管将变小以保证必要的飞行速度。 |