knee jerk

基本解释

Initially the knee jerk is to sell JPY, but the reality is that JPY strengthens dramatically.
最初大家的反應都是賣掉日元，但事實上，日元會非常戯劇化的走強。
It's impossible to say hello without smiling. One leads to the other just as a tap causes a knee jerk.
說“你好”的時候，是不可能不麪帶微笑的，而且能一個傳給另一個，正如敲擊膝蓋引起的條件反射。
blog.sina.com.cn
The knee jerk is a typical respondent .
膝反射是一種典型反射。
www.translation-dictionary.net

But she thoughtfully pleas for reasoned contemplation and discussion rather than knee jerk reactions.
FORBES: Frankenstein's Cat: New Book Shines Light on the 'Brave New World' of GMO Animals
Or was it just the threat of a knee jerk reaction against an obviously fragile financial system?
FORBES: Don't Invest In Political Footballs
Personally, I would really like to see more umpire consultations after a close call rather than the knee jerk reaction for instant replay.
FORBES: The Plight of The Umpires And The Inevitability Of Instant Replay