28. How does the author feel about the success of Sci-Hub?

【答案】[C] Concerned.

【解析】由第四段“thoroughly illegal”（完全违法）以及“the legal ecosystem has lost legitimacy among its users and must be transformed so that it works for all participants.”（法律的生态系统已经完全失去了其合法性，必须改变从而对所有参与者产生作用）可知作者对Sci-Hub 的产生非常担忧，认为现状急需改变。故选C。