地面砖镶贴时扫浆应用(). ["混合砂浆","界面剂","水泥砂浆","防腐剂"]
标准螺栓的长度间隔是多少?() ["1/16in","1/8in","1/32in","1/64in"]
纹枯病不危害()。 ["A、叶片","B、茎秆","C、稻穗","D、稻根"]
蒸法
以下是Nurbs标准几何体元素的有()。 ["A、面元素","B、定义曲线元素","C、壳元素","D、以上全部"]
计算题:某锅炉空气预热器出口温度为340℃,出口风压为3kPa,当地大气压力92110Pa,求空气预热器出口实际密度。(空气的标准密度为1.293kg/m3。)