1.
Fossils are early plants or animals once buried in earth, now hardened like rock.
化石是早期的植物或动物，过去埋在地下，现在坚如岩石。
2.
If there had not been a hard layer of rock beneath the soil,
如果不是因为土壤下面有一层坚硬的岩石，
3.
Crush some ice down and mix it with a small amount of common salt to produce a freezing mixture.
把诸如岩石等坚硬的东西压碎或碾成粉末。
4.
ledge rock
礁石, 坚石岩, 含矿[突出]岩石
5.
hard rock coring tool
坚硬岩石井壁取心器
6.
Any of various hard, dark - colored rocks, especially basalt and chert.
暗色岩一种坚硬、暗色的岩石，尤指玄武石及燧石
7.
sedimentary rocks,eg sandstone,limestone,slate
沉积岩（如砂岩、石灰岩、板岩）.
8.
Drilling and Blasting Technology of Hard Rock in New Ventilating Shaft in Zhangxin Coal Mine
张新矿新风井坚硬岩石凿岩爆破技术
9.
There were men, too, of a sturdier texture of mind than his, and endowed with a far greater share of shrewd, hard iron, or granite understanding;
也有些人比他具备更坚强的心地，富于更多的机敏和如钢铁或岩石般坚定的理解力；
10.
The strength of rock may be generally regarded as a measure of resistance of rock in breaking-up.
岩石坚固性可视为岩石抵抗破坏的一种度量。
11.
Any of various green rocks, such as serpentine.
蛇纹石一种绿色岩石，如蛇纹大理岩
12.
It is defeat that turns bone to flint;
是挫折使骨头坚如燧石；
13.
His purpose remains as firm as a rock.
他的意志仍坚如磐石。
14.
Of, relating to, or resembling rock, especially in hardness; stony.
坚硬的，石质的岩石的，与岩石有关的，或岩石状的，特别指硬度方面；坚硬的
15.
picturesque rocky shores
风景如画的岩石海岸
16.
A fire-resistant stone, such as certain sandstones.
耐火岩石耐火石，例如某种沙石
17.
Vitreous rocks are hard and shiny.
玻璃状的岩石坚硬而晶莹闪光。
18.
This machine can bore through solid rocks.
这台机器能够钻透坚硬的岩石。