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。
This time they fixed heavy metal clamps to both sides of the dish so that they could fasten the chains.
这次,他们用沉重的金属夹子把盘子夹住,以便往盘子上安装铁链。