This is a pen. The pen is a red 怎么改正确

This is a pen. The pen is a red 怎么改正确 this is red a pen的提问 The pen is red改成一般疑问句怎么改 Look This is a pen and it's red .The ruler is yellow.The key is,a,this,pen,red,连词成句 this is a red pen同义句转换 this is a red pen怎样改为一般疑问句 this is a red pen.and that is a green pen.（改为同义句） this is a this is a my pen Is this a your pen? This is a nice pen. what color is this pen的回答可不可以是It's a red pen