它们精细到连根部微小的短硬毛也模仿得栩栩如生, 就像生长在土壤中的植物. No hothouse or herbarium contains anything comparable; no wilted , browned specimens pressed between paper rival it.
本文研究了无造渣剂等矿石粉的耐磨堆焊电焊条.An overlay welding electrode without mineral powder as, slag forming medium, etc.介绍了用高碳铬铁渣做造渣剂冶炼锰硅合金的生产实践.The practice of smelting ferromanganese silicon with slag of high carbon ferrochrome is intr...