Reciprocating motion
[机] 往复运动
🧩 词语组成解析
[医] 交互的, 往复的
motion
['məuʃən]
n. 运动;手势;动机，意向;请求;
vt. 打手势;向某人点头或摇头示意;打手势要求[指示];
vi. 运动;打手势;
🗣️ 情景例句
A rolling stone gathers no moss.
滚石不生苔，转业不聚财。
A good book is a best friend who never turns his back upon us.
一本好书，莫逆之交。
It's about a time when there were black slaves in North America. It's about their fight for freedom.
（它）讲的是有一段时期，北美洲存在黑奴。影片讲述他们为自由而斗争的情况。