負反饋

negative feedback

to bear / to carry (on one's back) / to turn one's back on / to be defeated / negative (math. etc)

contrary / in reverse / inside out or upside down / to reverse / to return / to oppose / opposite / against / anti- / to rebel / to use analogy / instead / abbr. for 反切[fan3 qie4] phonetic system

to send back information / feedback

food / to make a present