在消费者和终端客户层面，不合格产品是在被购买和使用后退回的。

At the consumer or end-customer level, defective product comes back after purchase and some level of use.

youdao

在消费者和终端客户层面，不合格产品是在被购买和使用后退回的。

At the consumer or end-customer level, defective product comes back after purchase and some level of use.

youdao