The Air Force quickly became the think tank's main contractor, and Rand began consulting on everything from propeller turbines to missile defense.
空军很快成为了这家智库的主要承包商，兰德开始就从螺旋桨涡轮到导弹防御等一切问题进行咨询。
2
When a plane's propeller, for example, spins through a cloud, the propeller exerts a rearward force.
比如，当飞机的螺旋桨疾驰过云层时，会给云一个向后的作用力。
3
Through Hap’s connections, the Air Force quickly became the think tank’s main contractor, and RAND began consulting on everything from propeller turbines to missile defense.