let off
... let go (of) 松手放开 let off 排放,开枪,开炮 let out 放掉,发出 ...
cannon
... fortify 设要塞,加强 cannon 大炮;开炮 cask 桶,木通;装入木桶 ...
open fire
... flood the magezine 放水淹弹药库 open fire 开炮 cease firing 停止开炮 ...
firer
collaring
Shooting fired ; Firing ; Shot fired
"开炮"是个多义词,它可以指开炮(汉语词汇),开炮(APP)。