The concept of a particle is only approximate and has meaning only in the limit of small momenta.
粒子的概念只是近似的，并且只有在動(dòng)量較小的極限下才有意義。
利潤(rùn)不應(yīng)以犧牲地球和人民為代價(jià)。
I'm the reason your ears won't hear.