They spent 30 minutes on the bottom of the world before surfacing with their glass viewing ports cracked by the pressure.
30分钟后，他们的观察口玻璃出现裂缝，为防止被巨大的水压碾碎，行动终止并返航。
The welding rod has good wearing resistance and needn't warm before welding, which may be used to the surfacing of the roller.
该焊条耐磨性能好，焊前不预热，可用于轧辊的堆焊。
The welding rod has good wearing resistance and needn't warm before welding, which may be used to the surfacing of the roller.
该焊条耐磨性能好，焊前不预热，可用于轧辊的堆焊。
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