关门打狗

zhè zhǒng shè bèi bù jǐn kě yǐ zǔ jié dí rén hái kě yǐ yòu dí jìn rù hòu zài guān mén dǎ gǒu

这种设备不仅可以阻截敌人，还可以诱敌进入后再“关门打狗”。

But it was not used just to keep enemies out-it would also trap them inside so they could be attacked more easily!