问几个英语问题① which may not be altogether elevating but is hardly

问几个英语问题
① which may not be altogether elevating but is hardly poisonous中的elevating是什么词性
② Gregory Rodriguez reports that today’s immigration is neither at unprecedented level nor resistant to assimilation.中 neither at unprecedented level nor resistant to assimilation整个句子是做表语吗?
③Now,consider three indices of assimilation------language,home ownership and intermarriage.这个句子为什么没主语