物质: matter; substance; material 短语和例子可裂变物质 fissionable material; nuclear materials; 物质以三种形态存在: 固态、 液态和气态。 matter exists in three states: solid, liquid and gas.; 物质不灭定律 the law of conservation
单元: (自为一组的单位) unit; unit element; [计算机] cell; location; [电学] sub-unit; element 短语和例子运算单元 arithmetic unit; 记忆单元 memory location; 教学单元 teaching unit; 十八号楼四单元二号 no.2, entrance 4, building 18
