试压前要先封好盲板，认真检查管路是否连接正确，有无管内堵死现象。
Seal the blind plate and check carefully whether the pipeline is correctly connected and block phenomenon in the pipe before pressure test.
从公元前三世纪到明朝（1368-1644）经过多次修建的这堵用于捍卫帝国的墙现在正在坍塌。
Built in different stages from the third century B. C. to the Ming Dynasty (1368-1644), the wall was built to defend an empire but parts of it are now crumbling.
据报告，持枪者在进入该中心前门开火前，用他的汽车将中心的后门堵死了。
The gunman reportedly barricaded the rear door of the building with his car before entering the front door and opening fire.
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