短语词组短语Counter -sunk head 埋头;静心counter -sunk square neck bolt 埋头方颈螺栓d counter -sunk bolt 平顶埋头螺栓flat -headed counter-sunk bolt 平顶埋头螺栓half -counter-sunk rivet head 半埋头式铆钉头counter sunk head 埋头 返回 counter sunk