A.墊板長度不小于3跨,厚度不小于50mm B.墊板長度不小于2跨,厚度不小于50mm C.墊板長度不小于2跨,厚度不小于30mm D.墊板長度不小于3跨,厚度不小于30mm
A.大于100mm B.大于200mm C.大于300mm D.大于400mm
A.大于150mm B.小于150mm C.大于200mm D.小于200mm