We want three ______.Can you bring them to us?

A. piece of paper

B. pieces of papers

C. piece of papers

D. pieces of paper

D

句意：我们要三张纸。你能把它们带来吗？考查名词的数。paper作为“纸张”讲时是不可数名词，故B、C两项错误；piece是可数名词，three后接复数名词，排除A项。根据句意语境，可知选D。