It's difficult____at the back,so I don't like sitting behind the other students．[ ]

A. see    

B. seeing    

C. to see    

D. sees

对于已领未用、下月需要继续耗用的材料，一般可以采用"（）"办法。

A.预领料

B.返库后领

C.假退料

D.实地盘存