These pens are on sale,and you'd better buy some.为什么用on

Are these pens ___? These pens are your.henna These are my pens同义句 These pens _______ These pens are on sale,and you'd better buy some.为什么用on These are our pens .They are（）. These pens are().()are over there. Are these pens?是一般疑问句吗? These pens are blue 改为一般疑问句 Are these your pens 同意句 are these your pens?做肯定回答 are these your pens?不改原句,该句子 These are your pens,_______?如何做? These pens are yellow.改疑问句 Whose pens are these?(Betty)They____________. Are these his pens改为陈述句 Are these your pens?（同义句转换） Are these ------------ -------------- whose pens are these?还是whose are these pen?区别? 请问一下whose pens are these回答除了they are her pens是否还能回答成these pens are her或these are her pens?