Correct

往复

/ wǎngfù /
Strokes

Definition

to go and come back/to make a return trip/backwards and forwards (e.g. of piston or pump action)/to reciprocate (of machine part)

Example

As a Verb

move back and forth; reciprocate; move to and fro

1
Xúnhuánwǎng
循环往复
  
,
zhì
以至
qíong
无穷

repeat itself in endless cycles; be forever in a loop

2
Wǎng
往复
yùndòng
运动

reciprocating motion; alternating motion; backward and forward movement

As a Verb

contact; exchange visits

3
Shūxìn
书信
wǎng
往复

exchange letters