那个,句子中心并没有太大改变呀~原来natural gas是主语, the United States second biggest fuel source做其表语,但after crude oil离他要修饰的“排名”离得好远呀;改完后natural gas依然是主语,而the United States second biggest fuel source做了他的同位语,并且把after crude oil调到了他的修饰对象后,使整句 Natural gas is supplied almost exclusively from reserves in North America.主谓宾变得非常清晰而且意思明确!不知楼主是否认同
嗯……其实我说重心改变是因为原句说 natural gas is the United States second biggest fuel source and supplied almost exclusively from reserves in North America。 那么他想表达的意思就是natural gas is the United States second biggest fuel source 和 natural gas is supplied almost exclusively from reserves in North America这两个意思应该是平行相同重要的。而改过之后句子重心只剩下一个意思就是natural gas is supplied almost exclusively from reserves in North America.不过这个不重要拉!zhjwxx NN说的很清楚,(谢谢!)就是is 在这里没有办法承接,一个是V,一个是助V,绝对的错误。