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精品人妻久久久久一区二区三区,久久精品国产亚洲AV高清热,少妇被又大又粗又爽毛片黑人,欧美 日韩 亚洲 精品 成人,久久久久无码国产精品一区The General Institute of Machinery Group independently develops and produces various engineering materials, including high quality welding materials, green surface protection materials, advanced die materials and composite materials.
The Group independently develops and produces a series of key parts, including high-end precision castings, gear transmission units, precision forming parts and so on.
The General Machinery Institute Group has been engaged in foundry, welding and cutting, plastic forming, heat treatment, surface treatment and other technical fields for many years. It can provide relevant technical services and equipment.
China Academy of Machinery Science and Technology (CAM), founded in 1956, is...
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