He whistled and sang snatches of songs.他吹口哨并唱了几段小曲。Through the open windows snatches of melody float on the night air.乐曲断断续续地从敞开的窗户中飘出,在夜空中回荡.Breaks mutually after once again, first enters snatches seven competes.再度相互破发后...
Finally the structures were released in a 49 % HF etch.最后在49%F中腐蚀形成这些结构.More often , all of the materials etchant have a finite etch rate.剂中的材料都具有一定的刻蚀速率.Can some one suggest a suitable etch or sequence of etches to achi...