原式=32+2=42.
______all the homework assigned by the school the students have to work at it till midnight
A.Completing
B.To complete
C.Having completed
D.To have completed
为了减少振动,避免锯片铣刀折损,切断时通常应使铣刀外圆()
A.尽量高于工作底面
B.尽量低于工作底面
C.略高与工作底面