The use of machinery has superseded manual labour.机器的使用已经取代了手工劳动.Flintlock: Ignition system for firearms early 16 th century, It'superseded the matchlock and the wheel lock.燧发机: 火器点火系统,始于16世纪初, 取代火绳机和转轮打火机转轮打火机.Hand...
Vaccination immunizes people against smallpox.种牛痘可以免患天花.Vaccination immunizes one against smallpox.接种牛痘能使人免患天花.A health worker immunizes an infant in Nepal.医疗工作者在尼泊尔为婴儿注射预防针....