题目

如图所示的几何体的俯视图为(    ) 答案：D 【解析】 试题解析：从上往下看，易得一个正六边形和圆． 故选D． 考点：三视图.--- Was it by cutting down unnecessary expenditure ______ Mr. Simon saved the firm?--- No, it was by improving work efficiency.A. when B. what C. how D. that