— I've practiced a lot, but my spoken English isn't improving. What should I do?

— Why don't you ask your teacher for his _____?

A. plan

B. advice

C. reason

D. decision

手工锯轨、钻孔时，要把钢轨置平垫稳。不许手脚伸向轨下。不准用手指试探轨孔。