26. B。非限制性定语从句，which作表语。
【2012全国II】8. That evening, _____ I will tell you more about later, I ended up working very late.
A. that B. which C. what D. when
【答案】B
【解析】这里that evening是先行词，其在定语从句中作介词about的宾语，所以用which。句意：以后我将和你谈起的那个晚上，我工作到了很晚。
【考点定位】考查非限制性定语从句的关系词。
