压缩机机体产生不正常的振动，以下判断错误的是（）。
A.可能各轴承及十字头滑道间隙过小
B.可能由气缸振动引起
C.可能各部件结合不好
参考答案：A
“We ______ other possibilities too, such as murder. We ______ until we find convincing evidence.”said Detective Sam Peterson.
A. had looked at; wouldn’t give up B have looked at; don’t give up
C have considered; haven’t given up D. have been looking at; won’t give up
产褥期
