He managed to free one hand to ward off a punch.他设法挣脱出一只手来挡住了一拳。Many people swear by vitamin C's ability to ward off colds.许多人深信维生素C能预防感冒。Such a thin padded coat cannot ward off the cold mountain wind.这么薄的棉衣在高山上挡不住寒...
他拼命地闪身躲开一辆试图撞倒他的疾驰的汽车。He desperately dodged a speeding car trying to run him down.人群试图撞倒警察局的大门。The crowd tried to smash down the door of the police station.他被一辆公共汽车撞倒，一条腿折了。He was knocked over by a bus and broke his leg....
Mass flow information can be secured by using a densitometer.质量流量的数据可借助于密度计而获得.The zero point of the density scale is defined by having no specimen in the densitometer.定义密度计内设有样品时的密度为密度尺标的零点.Densitometer is an apparatus ...