av永久免费观看,日韩在线精品视频,在线观看国产视频,国产精品久久片,国产毛片av网站,国产又粗又硬又黄又刺激,国产黄色片视频

　　As the first batch of national intellectual property advantage enterprises announced by the State Intellectual Property Office, Xingtai Steel has always been promoting technological innovation based on the research concept of “accurate recognition, strict definition, fine analysis and precise improvement”. Now, Xingtal Steel could produce 3347 products which belong to 629 types of steel. Besides, 156 patents in force, including 50 patents for invention are obtained.