In old days, books for blind people used paper against metal wire to form letter

In old days, books for blind people used paper ____ against metal wire to form letters.

A.to press

B.pressing

C.pressed

D.which pressed

试题答案

C

考查非谓语动词，根据句子结构可知use paper to form letters,所以pressed against metal wire作paper的定语，即which was pressed against metal wire . 意为在古代，给盲人看的书用压在金属丝上面的纸来构成字。