Both watches have a stainless-steel case, an eye-catching crown and a black alligator leather strap. The watches allow for an engraving.
两款腕表均搭载精钢表壳、设计独特的表冠以及黑色鳄鱼皮表带。每枚腕表都可镌刻题字。
2
Composite pistons of various types are widely used in internal combustion engines, such as steelcrown and aluminium skirt type, inner and outer pistons type, and so on.
在内燃机中组合式活塞结构应用广泛，例如钢顶铝裙活塞、内外组合活塞等。
3
This paper expounds the shape classification of strip, analyzes the reasons why the shape wave occurs on the band steel in the cold rolling mill, and probes into the crown control of the band steel.