GGJJ,力矩是什么东东?有什么用呢?怎样用它证明三力汇交原理?THANK YOU VERY MUCH!

GGJJ,力矩是什么东东?有什么用呢?怎样用它证明三力汇交原理?THANK YOU VERY MUCH! Thank you very much! Thank you very much, you,much,thank,very Thank you very much. Thank you very much thank you very much~ 英语,用thank very much有没有错误 我记忆用有 thanks very much和thank you ve Thank you very much中的much是什么词? thank you very much thanks 英语翻译Thank you very much 急用,Thank You very much.