分析一句话英语的句子成分We should keep them informed of what is going on

你这题首先要理解这个词组：inform sb of sth通知某人某事/使某人知道某事.换成被动形式就是：sb be informed of sth.某人被通知（告知）某人.
再看句子里的keep them informed of .keep是谓语,them是宾语,后面一直到最后是宾语补足语.宾语与宾补语之间有逻辑上的被关系（them是被通知的）,就用了它的过分形式.这个过分形式里有个介词of它后面又接了自己的一个宾语从句.
This is a artist privileged to visit the gallery.是后置定语
We should make the artist privileged to visit the gallery是宾语补足语.
We should keep them informed单看也是完整的,但意思如果没有前后文的话,就有些不明.
“我们应该让他们知道（也就是被通知）”知道什么啊?没后文了,如：
---When will the meeting begin?
---Don't worry,I will keep you informed.(of when the meeting will begin).
回答语中,如果没有括号里的,也是完整的,因为前文有讲.
如果没有前文的话,就不知所云了.

informed of what is going on here宾语补足语，与them是逻辑上的主谓关系。informed of ...是不分家的，否则意思不完整
We should make the artist privileged to visit the gallery.中privileged to visit the gallery做宾语补足语
以上两句中的宾补事实上与...