论述钻铸铁材料时钻头主切削刃容易烧损的额原因。
参考答案:
铸铁材料导热性差,加工产生的是碎切屑,导致切削力和切削热都作用于靠近刀刃的前面上,所以刀刃易烧损。
He's got himself into a dangerous situation ____ he is likely to lose control over the plane. [ ]
A. where
B. which
C. what
D. why
佗术实工。(工)