Many scholars regard the pre-Hispanic civilizations of Peru as the most impressive in South America. (A) regard the pre-Hispanic civilizations of Peru as (B) regard the pre-Hispanic civilizations of Peru to be (C) regard the pre-Hispanic civilizations of Peru to have been (D) consider that the pre-Hispanic civilizations of Peru are (E) consider the pre-Hispanic civilizations of Peru as regard....as....和可以是名词也可以是形容词,对吗? 有regard to be 的用法吗?thanks a lot