电动机工作时发生剧烈振动，三相定子电流对称，可以判定是电动机—减速器—工作机构（部件）安装（）引起的。
参考答案：不同心
It is ________ my old camera, so I have just bought a new one.[ ]
A. too expensive to repair
B. so expensive that repair
C. expensive enough to repair
D. too expensive that repair
轨道衡的基坑用钢筋混凝土构筑，分为主坑和（）两个部分。
A、侧坑；
B、底坑；
C、边坑
