一千年前是什么朝代

Zhang Shengwu, a 60-year-old farmer from Maanshan, Anhui province, successfully built a submarine by himself, which has drawn widespread attention. The 5-metric-ton home-built submarine, named "Big Black Fish", can dive to 8 meters, CCTV News reported.

Zhang is a villager from Zhangdu village in Maanshan, Anhui province. He has been fascinated by invention since childhood. Over the years, Zhang has worked in carpentry, welding, and the shipping industry. Over 20 years ago, he returned to his hometown and built a wharf to sell sand, where he spent his days watching cargo ships come and go.