This is a pen. The pen is a red 怎么改正确在线等
问题描述：
This is a pen. The pen is a red 怎么改正确
在线等
答
This is a pen.The pen is a red
This is a pen.The pen is red多了个a
这是钢笔,这钢笔是红色的,red是形容词,不需要加数词a