The M16A2, in turn, is currently being supplemented by the M16A4, which incorporates the flattop receiver unit developed for the M4 Carbine.是什么意思_The M16A2, in turn, is currently being supplemented by the M16A4, which incorporates the flattop receiver unit developed for the M4 Carbine.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句