诚心请教~~~老题新问，新prep1-190

旅行的蜗牛

请教，一般形式的独立主格为n.+n. 同位语其中一种为n. , n. 那么怎么区分呢…？
190.The thirteen original British colonies in North America, some formed as commercial ventures, others as religious havens, each had a written charter that set forth its form of government and the rights of the colonists.
§A. some formed as commercial ventures, others as religious havens, each had a written charter
§B. some being formed as a commercial venture, others as religious havens, all of which had written charters
§C. some that formed as commercial ventures, others as religious havens, all had written charters
§D. with some being formed as a commercial venture, others as religious havens, all had a written charter
§E. with some formed as commercial ventures, while others as religious havens, each had a written charter

解释是some formed as commercial ventures, others as religious havens为同位语，可是同位语不是应该是n.加完整句子么
划线部分可以理解为一般形式的独立主格么？