求助曼哈顿上的一个语法点，急急急！！！

求助曼哈顿上的一个语法点，急急急！！！
Subgroup Modifiers

When you want to describe a part of a larger group with a modifier, use one of the following
three Subgroup Modifier constructions.

Right: This model explains all known subatomic particles, SOME OFWHICH
WEREonly recently discovered.
Right: This model explains all known subatomic particles, SOME OFTHEM
only recently discovered.
Right: This model explains all known subatomic particles, SOME only recently
discovered.



请教一下NN，红线的句子为什么them后面不加are阿？虽然读起来好通顺阿！！！

http://www.manhattangmat.com/forums/talk-about-absolute-phrases-t15360.html

这个链接应该全的了


看那个student的总结行了


因为他是抄论坛的。。。你看下面的instructor的回复就知道了

我还是想追问一下:
Right: His head held high, Owen walked out of the store
Right: Owen walked out of the store, his head held high.
Right: Owen walked out of the store with his head held high.

这三种都是独立主格吧,那前两种和同位语从句有什么区别啊,我比较混乱阿!!!
还有第三句with his head held high还是做伴随状语的吧，那和前面两种有什么区别阿！！！

nn们~来抢答吧！！！

you should use the context to determine


when a modifier is to provide some different things，then it should be an absolute phrase
when a modifier is to explain something ，then it should be an appositive modifier


The lady, our president, spoke out against racism.（apppsitive）


Tom paled when he came home, his mother standing in the
doorway.（absolute）


If they are exactly the same thing（just presented in different form；the lady is also the president），then it should be appositive


otherwise，absolute