题目

________of the land in that district________ covered with trees and grass. A . Two fifths; is B . Two fifth; are C . Two fifth; is D . Two fifths; are 答案：A在一次矿业开采中，施工人员挖掘到一金属块，为鉴定其为何种物质，人们用天平测得其质量为0.54kg，用排水法测得其体积是0.2dm3，这种金属的密度是2.7×103kg/m32.7×103kg/m3，可以初步判断这种物质可能是铝铝．若将此物体送到月球上，它的质量是0.540.54Kg．