hard-rock drilling硬岩层钻井;硬岩钻进
HARD OLD ROCK借我一生
as hard as rock坚如盘石
hard-rock driller硬岩钻工
hard-rock miner硬岩矿工
hard-rock geology硬岩地质学
hard-rock phosphate硬磷酸盐
hard base rock硬基岩
N-UNCOUNT（不可数名词） Hard rock is a type of very loud rock music with a fast beat. 硬摇滚乐; 强节奏摇滚乐 [oft N n]
...a hard rock band.
...一个硬摇滚乐乐队。