使用下列哪种方法可使切削温度下降（）
A、增大切削速度
B、增大刀具主偏角
C、增大背吃刀量
D、增大前角
参考答案：D
柴油的牌号按（）来划分。
A.密度
B.闪点
C.黏度
D.凝点
Health is very important to us, We should eat more vegetables and fruit instead of _____ rich food. [ ]
A. too much
B. much too
C. very much
