车刀前角增大，切削过程中的变形和摩擦减小，产生热量少，切削温度下降。但太大，使刀头体积减小，刀具散热差，切削温度上升。
参考答案：对
麻疹主要经（）传播。
A.接触
B.血液
C.飞沫呼吸道
D.消化道
E.虫媒
---My sister Sally had a bad cold. __________, she went to work as usual.
---She should go to see a doctor.
A．Though
B．Although
C．Because
D．However
