The compound material of resin matrix may produce serious smirch phenomenon during the minute hole drilling.
以樹(shù)脂為基體的復(fù)合材料在微孔加工中會(huì)產(chǎn)生嚴(yán)重污斑現(xiàn)象.
互聯(lián)網(wǎng)
"he had a smudge on his cheek"
"he made a huge blot on his copybook"
"The journalists have defamed me!" "The article in the paper sullied my reputation"