Question

第一句and of those在句子中是做什么语法成分？顺便分析句子语法结构？第二句which of these同问，谢谢！

（1）We studied rookie teachers working in really tough neighborhoods, asking which teachers are still going to be here in teaching by the end of the school year, and of those, who will be the most effective at improving learning outcomes for their students?
（2）We partnered with private companies, asking, which of these salespeople is going to keep their jobs?

Answer 1

第一句是这样的， asking后面跟了2个并列的宾语从句， 也就是asking which teachers are..., and (asking) who will be ...
of those 是指介宾短语作状语，those是指前文提到的“愿意留任到学期结束的那部分教师",
对这部分（愿意留任到学期结束）的教师，谁在提升教学效果方面成效最大呢？
相当于说 We asked that [in relation to those teachers / of those teachers], who will be the most...

第二句没什么特别啊， these这里是限定词修饰salespeople。这些销售中的哪一个会保住饭碗？
which of these people is going to... = which one of these people is going to
差别是第一个which是代词，第二个which one 的which是限定词。