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.
原句是对的，但是我怎么发现有两个谓语啊？ some formed 和 each had? each 是独立主格， 那独立主格可以是句子吗？
第二个问题： The World Wildlife Fund has declared that global warming, a phenomenon that most scientists agree is
caused by human beings’ burning of fossil fuels, will create havoc among migratory birds by altering the environment in ways harmful to their habitats.
这句是对的，那我怎么发现同位语是个句子啊？同位语可以是句子吗？
第二个问题。
The World Wildlife Fund has declared that global warming, a phenomenon that most scientists agree icaused by human beings’ burning of fossil fuels, will create havoc among migratory birds by altering the environment in ways harmful to their habitats.
同位语是a phenomenon that 。。。。（that从句是用来做定语修饰phenomenon的）
而这个同位语是对global warming具体化的解释性同位语。。
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.
原句是对的，但是我怎么发现有两个谓语啊？ some formed 和 each had? each 是独立主格， 那独立主格可以是句子吗？
我不太明白你的意思，独立主格一般是个名词或者名词短语，非谓语动词做状语，逻辑主语必须和主句一致，如果不一致的话，非谓语动词就要自己带主语，这个自己带的主语，就是独立主格。。
楼主你想问的是独立主格结构吧？？？
独立主格结构可分为一般独立主格结构——与主句逻辑松散
with引导的独立主格，与主句逻辑关系密切
each引导则强调句尾的复数名词，each+介词短语、adj短语、名词短语、ed/ing分词
others as religious havens, （each had a written charter） that set forth its form
就是典型的each引导的强调havens这个复数名词的独立主格结构
