SAT语法高手进(关于（非）限制性定语从句)

SAT语法部分有关非限定定语从句的内容是不是和高中英语不一样?
比如说这题,
During the summer months,several thousand people a day visit the park,which is known for its waterfalls and rock formations.
为什么这里的which可以指代park呢?我选这句,
During the summer months,knowing its waterfalls and rock formations,several thousand people a day visit the park.怎么就错了呢?
答：原题是：
During the summer months,several thousand people a day visit the park,which is known for its waterfalls and rock formations.
(A) During the summer months,several thousand people a day visit the park,which is known for its waterfalls and rock formations.
(B) Known for its waterfalls and rock formations,several thousand people a day visit the park
during the summer months.
(C) Several thousand people a day visit the park during the summer months known for its waterfalls and rock formations.
(D) Several thousand people had visited the park a day,which is known for its waterfalls and rock formations during the summer months.
(E) During the summer months,knowing its waterfalls and rock formations,several thousand people a day visit the park.
只要回答E有错误就可以了.E句主句在最后,During是时间状语,knowing ...是现在分词,也可以作状语,可以看作是原因吧.因为知道,了解它的瀑布和岩石构造,所以每天有几千人去游览那个公园.
此句不妥有二：1.its 指代不明.前面没有提及公园,突然冒出个its,让人莫名其妙.2.既然知道了,还去游览什么?
显然没有原句意思好：
夏天的几个月期间,每天有几千人去游览那个公园,该公园因其瀑布和岩石构造而闻名.
下面这题也是相同的疑问：
Many colleges are adopting work-study programs,which offer practical advantages to both the student and the institutions.
选offer而不是offers,说明这个which指代的也是programs,而不是逗号前的一整句话.和高中语法不一样.
答：楼主应了解,非限制性定语从句不仅可指代整个句子,更可指代其中的一个词或一个部分.

语法不分高中小学，都一样，which修饰的是先行词，先行词可以是一个词，也可以是前面的一个句子表达的一件事
He has failed in the exam,which makes him upset. 指的句子
He has failed in the exam，which is very important to him. 指的是exam

which可指代整句话，也可指代单个的物，在从句中充当主语或宾语。
。。。 ，which is known for its waterfalls and rock formations.（which）就在从句作主语