船舶柴油机在经过修理后,如果更换了气缸套或活塞环、或更换了轴瓦,当投入正常运转之前的磨合过程______。
A. 可以省略
B. 绝对不可省略
C. 根据情况而定
D. 随意
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活塞环与气缸套磨合不良就投入使用,必然会产生严重的______。
A. 黏着磨损
B. 微动磨损
C. 腐蚀磨损
D. 磨粒磨损
The first paragraph tells us that there’s good news for both online merchants and consumers.
A. 对
B. 错
E-commerce will shrink because online rip-offs of shoppers are on the rise.
A. 对
B. 错
The economic turmoil has occurred in the United States.
A. 对
B. 错