I will buy this book because from that I study a lot.(有because作为连接词，不用“介词+which”结构连接)
I will buy this book from which I study a lot.(无连接词，需要用“介词+which”结构连接)
一般例子就不用举了，只举个比较特别例子“A of B, which”(注：这里的of表示从属关系)
1，The commission proposed that funding for development of the park, which could be open to the public early next year, be obtained through a local bond issue.
2,Construction of the Roman Colosseum, which was officially known as the Flavian Amphitheater, began in A.D.69, during the reign of Vespasian, and was completed the Colosseum with a one-hundred-day cycle of religious pageants, gladitorial games, and spectacles.
3，In laboratory rats, a low dose of aspirin usually suffices to block production of thromboxane, a substance that promotes blood clotting, but does not seriously interfere with the production of prostacyclin, which prevents clotting.
4，The survival of coral colonies, which are composed of innumerable tiny polyps living in a symbiotic relationship with brilliantly colored algae, is being threatened, experts say, not only by pollutants such as agricultural runoff, oil slicks, and trash, but also by dropped anchors, probing divers, and global warming.,
5，In attempting to solve the problems caused by a lowering of the price of oil, oil companies operating in the North Sea have taken a variety of approaches, which include reducing employment, using new technology to pump oil more efficiently from smaller fields, and finding innovative ways to cut the cost of building and operating platforms.,
这些例子都能说明从属关系“A of B，which”中的which就近修饰紧邻的名词B。但是需要注意的是，在“SVO,which”句型中，如果which指代S一定错误，which如果指代主语，这样使用:s+verb,which
From the bark of the paper birch tree the Menomini crafted a canoe about twenty feet long and two feet wide, with small ribs and rails of cedar, which could carry four persons or eight hundred pounds of baggage so light that a person could easily portage it around impeding rapids.
(A)baggage so light
(B) baggage being so light
(C) baggage, yet being so light
(D) baggage, and so light
(E) baggage yet was so light
Emily Dickinson’s letters to Susan Huntington Dickinson were written over a period beginning a few years before Susan’s marriage to Emily’s brother and ending shortly before Emily’s death in 1886, outnumbering her letters to anyone else.
A,Dickinson were written over a period beginning a few years before Susan’s marriage to Emily’s brother and ending shortly before Emily’s death in 1886, outnumbering
B,Dickinson were written over a period that begins a few years before Susan’s marriage to Emily’s brother and ended shortly before Emily’s death in 1886, outnumber
C,Dickinson, written over a period beginning a few years before Susan’s marriage to Emily’s brother and that ends shortly before Emily’s death in 1886and outnumbering
D,Dickinson, which were written over a period beginning a few years before Susan’s marriage to Emily’s brother, ending shortly before Emily’s death in 1886, and outnumbering
E,Dickinson, which were written over a period beginning a few years before Susan’s marriage to Emily’s brother and ending shortly before Emily’s death in 1886, outnumber
这句话的which不能修饰其紧邻的名词Susan Huntington Dickinson，必须跳过介词结构to…，修饰核心词letter。
Unlike most other mergers in the utility industry, which have been driven by the need to save money and extend companies’ service areas, the merger of the nation’s leading gas company and leading electric company is intended to create a huge network for marketing the utilities in question as states open their utility markets to competition.
In order to protect English manufacturers of woolen goods against both American and Irish competition, England passed the Woolens Act of 1698, which prohibited the export of woolen cloth beyond a colony&aposs borders.
One pervasive theory explains the introduction of breakfast cereals in the early 1900s as a result of the growing number of automobiles, which led to a decline in horse ownership and a subsequent grain glut
Glut n. (商品)供过于求;大量
The Forbidden City in Beijing, from which the emperors ruled by heavenly mandate, was a site which no commoner or foreigner could enter without permission, on pain of death.
有人这里会说这不是A of B，which吗?which应该紧邻修饰啊?其实不然，因为of 1968和前面的那些A of B实际上用法不一样，这里是表示时间而不是“从属关系”。这个时间应该归在介词结构一类，所以要跳过。