Other scientists perform the specialized work of peer review also for free, because it is a central element in the acquisition of status and the production of scientific knowledge.
其他科学家从事同行评议的专业工作也是免费的，因为这是获得学术地位和产出科学知识的一个核心因素。
3
It is free but also illegal through much of Europe, so there is some element of risk involved, plus the only washing facilities are generally a nearby river (if we're lucky).