Pulling

来自Big Physics

google

ref

Old English pullian ‘pluck, snatch’; origin uncertain; the sense has developed from expressing a short sharp action to one of sustained force.


文件:Ety img pulling.png

wiktionary

ref

From Middle English *pullynge, equivalent to pull +‎ -ing.

From Middle English pulling, pullyng, pullynge, equivalent to pull +‎ -ing.