break down :故障
claim :n.(保險)理賠;費用申請
complaint :n.抱怨;不滿
criticism :n.批評
defective :a.瑕疵的;有缺陷的
feedback :n.意見反映
improve :v.改進;改善
invalid :a.無效的
price list :價目表
product quality :產(chǎn)品質(zhì)量
purchase :n.購買
refund :n.退費
replacement :n.更換
warranty :n.保固