(每日一词）rattle

Rattle  /ˈræt̬.əl/ v. （连续重复的）嗒嗒声，嘎嘎声；连续短促的碰撞声

meaning: a sound similar to a series of quickly repeated knocks 

1) 对比：rattle/battle 

2) 联系：r--ring 

e.g. From across the town came the rattle of machine-gun fire. 从城镇的另一边传来机关枪开火的嗒嗒声。