你一定注意到他有时候显得特别疲惫。You must have noticed how tired he sometimes looks.他正挥手以引起他们的注意。He was waving his arms to draw their attention.罗斯听到了熟悉的声音，但没注意听说的是什么。Rose heard the familiar voice, but tuned out the words....
脆性往往是合金化的一种结果.Brittleness is often a result of alloying.表面涂敷技术分为两个主要类型: 脆性涂层和光弹性涂层.Surface - coating techniques may be classified into two major types: brittle coatings and photoelastic coatings.研究裂纹技术应用于分离脆性块体的分离理论和分离方法...