a reversing key的意思|示意

It must have taken me a half hour to sense that maybe some key to an answer could result from reversing the word "Thanksgiving" — at least that suggested a verbal direction, "giving thanks."

大概过了半个小时左右我才意识到，问题的关键也许在于把Thanksgiving这个字前后颠倒一下——那样一来至少文字好懂了：giving thanks。

Reversing the polarity of a key, such that material formerly keyed out will be keyed in, and vice versa.

反转一个键的性质，这样一来素材中先前是键出的将变为键入，反之亦然。

As a key to tunnel smoke control, the critical velocity refers to a minimum vertical ventilation velocity which can effectively control the smoke under the direction of fire source without reversing.

临界风速是隧道烟气控制的关键所在，其指隧道火灾过程中能有效控制烟气于火源下风方向而不发生逆流的最小纵向通风风速。