He tore up the letter angrily and threw it into the wastebasket.他气愤地把信撕掉,扔进字纸篓里.While nobody was looking, she squashed her school hat and crammed it into a wastebasket.趁没人看见，她把校帽弄扁塞进了废纸篓。Thomas crumpled the empty envelop...
如果冲量为零, 则动量不变.If the impulse is zero, there is no change in momentum.正周相动力冲量的定义可以用类似的式子表示.The positive phase dynamic impulse can be defined by a similar expression.用于碰撞过程的动量定理——冲量定理.The momentum theorem applied to an imp...