基本解釋耐火等級(jí)詞組短語(yǔ)短語(yǔ)calculated fire resistance rating 耐火極限的計(jì)算Fire Resistance Class Rating 阻燃性評(píng)估等級(jí)fire resistance rating更多詞組專(zhuān)業(yè)釋義土木建筑工程耐火等級(jí)耐火極限