The main material of most masks is polypropylene.

大多数口罩的主要材料是聚丙烯。

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Combinatorial material chip technology provides a new way to fabricate multi-element arrays with different parameters on the same substrate by using a series of masks.

组合材料芯片技术是用一系列掩膜在同一块基片上获得含不同参数单元样品面阵的方法。

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He leads a committee of supply-chain executives, currently focused on 18 "high-impact" opportunities to improve efficiency in making major products, including respiratory face masks, stethoscopes and reflective material for highway signs.

WSJ: 3M Begins Untangling Its 'Hairballs'

The profuse material culture of handcrafted objects includes floats, costumes, head ornaments and animal masks.

UNESCO: Intangible Cultural Heritage