外圆形状复杂,内孔形状简单的工件,应选择()作定位基准
参考答案:内孔
A thief broke into the house at midnight, ______ the house in a mess .[ ]
A. left
B. to leave
C. leaving
D. leaves
变压器套管有严重的破损和放电现象,可以观察一段时间。