Using _____ illegal drugs can lead to health problems, and it can be _____ stain on one’s life.

A．不填；the

B．the; the

C．the; a

D．不填； a

YB95型条盒透明纸包装机透明纸供给机构的作用是将透明纸在扇形输送辊的作用下，通过各级导纸辊被（）后送至切刀装置。