—My pen is lost and I can't find it anywhere.

一So you will have to buy  ______.[ ]

A. it

B. few

C. one

D. any

（）是指以作者本人的研究工作或研制成果为依据撰写，已经公开发行进入社会流通。

A.零次文献

B.一次文献

C.二次文献

D.三次文献