康康map-
1.He（主语） described（谓语动词） it（宾语） as（as引出宾语补足语） "a very agreeable situation located（过去分词做后置定语，修饰situation） within（介词，两者之间，指两座小山之间） two small hills in the midst of which（这里的which应当包括前面的组合介词in the midst of，这是一个带有复合介词in the midst of的定语从句，先行词是two small hills） flowed a great river."
2.They（主语） support（谓语动词） the cables（宾语） from which the bridge has been suspended（这是带有介词from的定语从句，先行词是cables）. 这一句里没有状语。但是，from which在定语从句里做状语。
这两句是新概念英语第三册中一篇文章的。
黑桃云-
1.He described it as "a very agreeable situation located within two small hills in the midst of which flowed a great river."
他对该港作了这样的描述：“地理位置十分适宜，位于两座小山的中间，一条大河从中间流过”
句子主干是he described it as "a very agreeable situation
主语he 谓语 described 宾语it 宾语补足语 "a very agreeable situation
located within two small hills是分词做定语，修饰前面的agreeable situation ，相当于which is located within two small hills ,说明是怎样适宜的地理位置呢，是位于两座小山的中间的位置
in the midst of which flowed a great river
这里也是定语从句，来修饰前面的two small hills ，是那两座中间有条大河的山。
which在这里是指the two small hills
同时这里用了倒装，正常语序是 a great river flowed in the midst of the two small hills,山的中间有条河流
2.They support the cables from which the bridge has been suspended.
高塔支撑着钢缆，而钢缆又悬吊着大桥，
句子主干They support the cables
主语they 谓语support 宾语 the cables
后面是定语从句，修饰the cables
which代替cables, 句子还原语序是the bridge has been suspended from the cables 大桥被钢缆悬吊着
Chen-
1句中主语：he
谓语described
宾语：it
宾语补足语：as a very agreeable situation
located within two small hills和 in the midst of which flowed a great river.可以看做定语从句，修饰situation
当然也可以将as和后面的引语整体看做宾补
大鱼炖火锅-
1句中主语：he
谓语described
宾语：it
宾语补足语：as a very agreeable situation
located within two small hills和 in the midst of which flowed a great river.可以看做定语从句，修饰situation
当然也可以将as和后面的引语整体看做宾补
阿啵呲嘚-
within 内
副词 名词 介词
时间内 里 在...之内
which 这
形容词 代词
何 哪
孰 哪一个
我不懂运营-
汗