reciprocation

名词 reciprocation:

1. the act of making or doing something in return
2. alternating back-and-forth movement
3. mutual interaction; the activity of reciprocating or exchanging (especially information)
   同义词：interchange, give-and-take

re.cip.ro.ca.tion

n.（名词）
An alternating back-and-forth movement.
往复运动：交互地前后运动
The act or fact of reciprocating; interchange.
回报；互换：报答的行为或事实；交换