| 1. | This phrase is borrowed from the aeronautics flight testing industry of the 1950 ’ s , when pilots flew increasingly faster , or “ pushing the envelope ” , eventually breaking through the sound barrier and further 这一个片语从1950年代的航空学飞行测试业被借,当飞行员逐渐地更快速地飞了的时候,或"推到极限" ,最后突破健全的障碍和比较远的。 |