When you wave your arms up and down in a straight line，it means"yes"．

当你在一条直线上下挥动手臂时，它的意思是“是的”。

youdao

It's a wave, not a straight line.

生活是不是直线，而是波浪线。

youdao

A sawtooth wave rises (or falls) in a straight line from a starting point to an ending point, at which time it instantaneously jumps back to the starting value.

锯齿波从某一始点到某一终点沿着一条直线上升(或者下降)，在终点的时候它马上跃迁回其起始值。

youdao

Because a surfer stays just ahead of the break, a wave that breaks very slowly carries him straight towards shore at only the speed of the wave.

ECONOMIST: On the beach

Loading his rosters with young players and castoffs who came cheaply and fit the bill on the new stats wave, he got the A's into the playoffs for four straight seasons from 2000 to 2003.

FORBES: Sports Business