It's projected to cost more than $2,300 to heat a typical home with heating oil this winter.1.to heat…感觉是cost的逻辑主语,但这样不就少了it作为形式主语吗?2.heating oil中heating是动名词还是现在分词
请解释这个句子中long ago的用法:Stone does not decay, and so the tools of long ago have remained when even the bones of the men who made them have disappeared without trace. 句子选自《新概念英语》4册第一课