variable-area propelling nozzle

例句：

1. 1.The variable-area propelling nozzle is a critical component in the design of spacecraft engines.
   可变面积推进喷嘴是航天飞机发动机设计中的关键部件。
2. 2.The variable-area propelling nozzle was developed to improve the efficiency of the vehicle's thrusters.
   可变面积推进喷嘴被开发出来，以提高车辆喷气推进器的工作效率。
3. 3.The variable-area propelling nozzle has been tested in various environments, including high altitudes and extreme temperatures.
   可变面积推进喷嘴已经在各种环境中进行了测试，包括高海拔和极端温度。