Although undoubtedly an ingenious water-saving tool, many have questioned its flexibility, particularly for those that need to wash their hair - an exercise which will certainly last longer than four minutes. 毫无疑问,这是很有创意的节水工具,但是很多人质疑它缺乏灵活性,特别是那些要洗头发的人,洗头发花费的时间肯定会超过四分钟。