I watched my master's face pass from amiability to sternness; he hoped I was not beginning to idle.
我看着老师的脸色从和蔼变得严肃；他希望我不是开始放松学业了。
Successful practice shows the application of such backfill material to abandoned roadway is a good solution to ensure the working face pass through abandoned roadway quickly, sa...
实践证明，采用高水速凝材料充填空巷是综放工作面快速、安全、经济地推过空巷的有效途径。
Successful practice shows the application of such backfill material to abandoned roadway is a good solution to ensure the working face pass through abandoned roadway quickly, sa...
实践证明，采用高水速凝材料充填空巷是综放工作面快速、安全、经济地推过空巷的有效途径。
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