轴线平面相交斜钻削存在哪些困难?
参考答案:钻轴线平面相交斜深孔钻头容易偏斜,孔中心位置不易保证,钻孔中轴线容易歪斜,结果导致两孔轴线不能相交和交叉多彩度误差大。
简述畜禽肉类主要卫生问题。
1. I have two ____________. ( knife)
2. Whose ______________ are these ? ( child )
3. These photos are hers. They are not ____________. (I)
4. What about ____________ shopping? (go)
5. The little girl is ____________ on her hat now. (put)