铁板钉钉

Explanation: ① still made head-on. Metaphor speak and act firmly, simply. ② metaphor has become conclusive. 　　Source: Fan Naicheng "little fairy technician hand over" [old man] the hands of the right hand of the pipe toward the secretary's plan point points, iron nails out of words like collapsing 'I object! '" 　　Examples: Her Life in the leaves of the Commissioner is Erniu Er, has ~, not to be suspicious. ★ "Flower City" No. 6 1981