?超硬钢
... extirpator深耕中耕机 extra hard steel超硬钢 extra high pressure超高压 ...
?特硬钢
... They Worked Extra Hard 他们工作特别努力 Think Extra Hard 想加倍努力 Extra Hard Steel 特硬钢 ; 超硬钢 ...
极硬钢
Further, says Peabody, world steel production is up 8% this year, requiring an added 75 million tons of extra hard and hot-burning metallurgical coal.
FORBES: Peabody Earnings Up, Coal Supercycle Just Beginning
英汉双解词典包含3185865条英汉词条，基本涵盖了全部常用单词的翻译及用法，是英语学习的有利工具。