It is no use talking about the things of (

It is no use talking about the things we are not sure of
这里是个定语从句,the things这个是先行词,所选成分要在从句中做介词的宾语,
A which
关系代词which/whom在定语从句中做介词的宾语时,从句常用＂介词+Which/whom＂引出,有时也用＂介词+whose+名词＂
介词后可以跟Wh-开头的宾语从句.
引导词：whether[是否]、what、who、whom、Whose、when、Where、why、how.