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。
It sped downhill at the end of the race and its driver had a lot of trouble trying to stop it.
它在接近终点时,冲下了山坡,驾驶员费了好大劲才把车停下来。