A:two thirds; wear; 60 percent
B:two thirds; wear; 60 percent
C:two third; wears; 60 percent
D:two third; wears; 60 percent
嫦娥三号探测器成功落月,标志我国首次实现地外天体软着落。据不完全统计,有230多家单位参与研制嫦娥三号探测器。这说明 ( )
在光滑的水平面上有一个物体靠墙静止着,如图所示.