The pen well, so it well.
A. is written, is sold
B. is writing, is selling
C. is written, sells
D. writes, sells
网友回答
A. is written, is sold
B. is writing, is selling
C. is written, sells
(答案→)D. writes, sells
解析：原句意思是，这种钢笔很好写，所以它很好卖。这里表示“好写 ”“很好卖”的意思，所以应该用一般现在时的主动语态，所以选D。