行为监督最直接、最有效的方式是()
A.观察
B.直接监督
C.目标管理
D.行政控制
E.反馈
参考答案:B
28. At a rough look, the area of the city is about ______ the old one.
A.three times the size as
B.three times the size of
C.three times that is
D.three times what is
简述数控折弯机开机操作步骤。