1．Most museums in the world keep things from the past _____ people should know about.
A．what B．as C．that D．when
【答案】C
【解析】考查定语从句关系词。句意：世界上大多数博物馆保存着人们应该知道的关于过去的东西。分析句子成分可知，先行词为the past，从句主语为people，谓语为should know about，可知此处缺少宾语，应使用关系代词that/which引导定语从句，that/which在句中充当宾语。故选C。
2．Here is my classmate _____ bicycle was lost yesterday.
A．his B．that C．whose D．which
【答案】C
【解析】考查定语从句。句意：这是我的同学他的自行车昨天丢了。先行词为my classmate，在后面的定语从句中作定语，所以关系代词为whose。故选C项。
3．This factory _____ produced paper was closed yesterday because it had caused too much pollution.
A．which B．where C．it D．what
【答案】A
【解析】考查定语从句。句意：这家造纸厂昨天关闭了，因为它造成了太多的污染。此处factory是先行词，指物，在后面的定语从句作主语，所以这里用which或that引导定语从句，故选A。
