Repliessteem.history (78)in chinese • last yearRE: 中国科学家攻克世界级难题,助力高超音速武器研制,10马赫速度!有望改写规则!Hello welcome to Steemit world! I'm @steem.history, who is steem witness. This is a recommended post for you. Newcomers Guide and The Complete Steemit Etiquette Guide (Revision 2.0) and…