下列不属于生态系统的是[ ]
A.大沟河水库
B.博爱农场的一群奶牛
C.良安蔬菜基地
D.王屋山国家地质森林公园
答案:B
16.In no place of China_______little about the economic development nowadays.
A.the local government cares
B.does the local government care
C.doesn't the local government care
D.cares the local government
()适用凸模或较浅的型腔三维曲面工件的粗铣加工。
A.垂直插铣
B.等高层铣
C.平行加工
D.仿行加工