机件磨损的过程大致可分为几个阶段？每个阶段的特征如何？
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No sooner （） than they started to repair the sludge pump.
A. the second engineer had got into the engine room
B. the second engineer got into the engine room
C. has the second engineer got into the engine room
D. did the second engineer get into the engine room
东河区妇女发展规划实施细则规定提升儿童（），提高家庭教育的水平和质量。
斜Y形坡口对接裂纹试件中间的试验焊缝不论板厚多少，一律（）。
A. 只焊一道
B. 只焊两道
C. 只焊三道
D. 只焊四道
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