Do you have a discount _the clothes?I hope I can buy them_a 20% discount.

问题描述:

Do you have a discount _the clothes?I hope I can buy them_a 20% discount.

on,at

1:of a discount of 是个短语。打折的意思
2:at at a 20% discount 意识是减少20%的价格俗语就是打8折吧。。
应该是对的额(第二个不太确定)

on ;by;

a