How did the speaker comment on Gerome’s speech

A．Gerome spoke last but not best.

B．Gerome spoke last but the best.

C．Although last, Gerome spoke fast.

D．Gerome spoke at a speech.

钻孔时，切削深度是由（）决定的。

A、进给量

B、切削速度

C、钻头直径

D、钻头横刃