1.
a rattling noise (often produced by rapid movement).
坚硬物体碰撞时产生的一连串尖锐的碰撞声。
2.
"Grinding machine:Machine tool that uses a rotating abrasive grinding wheel to change the shape or dimensions of a hard, usually metallic, workpiece."
磨床:用旋转的砂轮改变坚硬物体(通常是金属)的形状和尺寸的机床。
3.
a rattling sound as of hard things striking together.
类似坚硬的物体互相撞击的卡嗒声。
4.
(biology) the normal rigid state of fullness of a cell or blood vessel or capillary resulting from pressure of the contents against the wall or membrane.
内部充满物体而饱满坚硬的状态。
5.
tough more-or-less rigid protective covering of an animal or plant.
动植物体外坚韧且有些坚硬的起保护作用的遮盖物。
6.
hard outer covering or case of certain organisms such as arthropods and turtles.
某些有机体像节肢动物和海龟的坚硬的外壳。
7.
"Bone: Rigid connective tissue of vertebrates, consisting of cells embedded in a hard matrix."
骨: 脊椎动物体内坚硬的结缔组织,主要由坚硬的骨基质和嵌在其中的骨细胞构成。
8.
" Bone： Rigid connective tissue of vertebrates, consisting of cells embedded in a hard matrix."
骨:脊椎动物体内坚硬的结缔组织，主要由坚硬的骨基质和嵌在其中的骨细胞构成。
9.
any of a group of hard crystalline minerals that consist of aluminum silicates of potassium or sodium or calcium or barium.
任何一组坚硬的晶体矿物，由含有钾、钠、钙、钡的铝硅酸盐组成。
10.
marine mollusks having a rough irregular shell; found on the sea bed mostly in coastal waters.
有坚硬的不规则形状壳的海生软体动物；大多在海岸的海滩上。
11.
Stones are hard, water is wet, objects unsupported fall towards the earth's centre.
石头毕竟坚硬，水毕竟潮湿，悬空的物体毕竟落向地心。
12.
Main influ-encing factors on rock abrasiveness are the sturdiness of rock mass and contentof hard minerals,and the coefficient of rock abrasiveness is a function of thespecific energy consumption in drilling and the content of hard minerals.
影响岩石磨蚀性的主要因素是岩石的整体坚固程度和硬矿物含量。
13.
the act of making something harder (firmer or tighter or more compact).
使某物变硬的行为（坚硬或牢固或更加紧凑）。
14.
the material that forms the hard outer covering of many animals.
覆盖许多动物外表的坚硬材料。
15.
Diamonds are the hardest substance in nature.
⑵金刚石是自然界最坚硬的物质。
16.
very hard mineral used as an abrasive.
一种极为坚硬的矿物，用作研磨剂。
17.
"a coating that dries to a hard, glossy finish:"
漆干后成坚硬、光滑的覆盖物.
18.
the hard fibrous lignified substance under the bark of trees.
树皮下坚硬多孔的木质化物质。