First you must find out the clause of the quality problems and furnish sufficient evidence.
首先你的查查有关质量问题的条款,并提供足够的证据。
Fifty-litre carboy would be the most economical size. Carboys may be retained without charge for two months.
50升的瓶子应是最经济的尺码,这些瓶子可免费保存两个月。