We already have pencils, but we need two pens.
A. dozen of ; dozen
B. dozens of ; dozens
C. dozens of ; dozen
D. dozen; dozen
网友回答
A. dozen of ; dozen
B. dozens of ; dozens
(答案→)C. dozens of ; dozen
D. dozen; dozen
解析：考察固定用法。Dozens of许多，大量；dozen前面有数词时，接dozen原形。故C正确。句意：我们已经有了很多铅笔，但是我们还需要2打钢笔。