This paper introduced the technical of using drilling downward hole from working surfale in protective coat bottom tu pull out goaf gas, and the effects were analysed and summarized.

前言： 介绍了在被保护层底板巷向保护层工作面施工下向穿层钻孔，抽采保护层工作面采空区瓦斯的具体做法，并对取得的效果进行了分析总结。

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The charcoal works have a different weight, partly due to the black colour, but also because they have a slightly watery sheen from the protective coat of resin, and due to their simple organic forms.

木炭作品的重量不一样，一部分是由于黑色的缘故，但是也因为它们有一层保护性的树脂发出轻微的水样光辉，并且也由于它们简单的有机式样。

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Myelin, a protective substance, is beginning to coat the spinal column.

髓磷脂是一种防护物质，它开始覆盖在脊柱的表面。

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Unlike nerve cells in the rest of the brain which are covered with protective myelin, the nerve cells in the retina are bare with no myelin coat.

BBC: Simple eye scan can reveal extent of Multiple Sclerosis