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。
They will hardly know which facts to select from the great mass of evidence that steadily accumulates.
对于逐渐积累起来的庞大材料,他们几乎不知道选取哪些好,