there's only one problem（） they propose A about which B of which C on which D that

来源：学生作业学帮网编辑：学帮网时间：2024/06/06 05:23:33

D定语从句的先行词有only修饰的时候,只能用that作引导词

B of which

there's only one problem（ ） they propose A about which B of which C on which D that