The Verrazano Bridge,which was designed by Othmar Ammann,joi

Verrazano,an Italian about whom little is known,sailed into New York Harbour in 1524.1524年,一位鲜为人知的意大利人维拉萨诺开船驶进了纽约港.
1.这里的about是什么意思 2.为什么是whom而不是who 3.为什么是little is known is little known

求分析新概念三17课第一句：Verrazano,an Italian about whom little is known.
Verrazano,an Italian about whom little is known,sailed into New York Harbour in 1524 and named it Angouleme.
关于这句话主要是an Italian about whom little is known,理解不清楚,首先我知道这句话是Verrazano的同位语,whom引导定语从句,
1：little的词性是什么,是名词?还是副词?
若little是名词,这句话就应该改成perter,an italian about whom little know,sailed into new york harbour.
若little是副词,这句话也应该改成perter,an italian about whom is little known,sailed into york harbour.
难道这是倒装句吗?又是怎么倒装的呀?
还是说little作为副词就应该放在be动词的前面?可我凭语感little就应该放在is的后面呀!
2：little如果是副词的话,whom在从句中到底做什么成分?whom指代的应该是an Italian,如果在从句中做主语的话,应该用who啊:an Italian who is little known,而这个about怎么解释,about后面一定会跟介词宾语,如果是about an italian的话,关系代词在从句中指代的应该是宾语,而about会提前到关系代词前面,那么也就是原句an Italian about whom little is known,不过这样的话,定语从句中主语是什么?
我是晕了,百思不得其解,搜了搜百度,虽然有相同的问题,但也没得到想到的答案.答得好会加分的.

新概念英语第三册 17课语法
请先耐心看完这一段：
he Verrazano Bridge,which was designed by Othmar Ammann,joins Brooklyn to Staten Island.It has a span of 4,260 feet.Two great towers support four huge cables.The towers are built on immense underwater platforms make of steel and concrete.The platforms extend to a depth of over 100 feet under the sea.Above the surface of the water,the towers rise to a height of nearly 700 feet.They support the cables from which the bridge has been suspended.Each of the four cables contains 26,108 lengths of wire.It has been estimated that if the bridge were packed with cars,it would still only be carrying a third of its total capacity.
提问1：They support the cables from which the bridge has been suspended.是怎么回事?the bridge has been suspended from the cables?我没出要用from的原因
提问2：It has been estimated that if the bridge were packed with cars,it would still only be carrying a third of its total capacity.为什么是be carrying?我知道这句是虚拟,但是前面已经虚拟了,这和后面那句没什么关系吧?

新概念英语3第17课. 5 The Verrazano Bridge, ______ the design of Othmar Ammann.
5 The Verrazano Bridge, ______ the design of Othmar Ammann. (1. 8)　　a．is　　b．was　　c．were　　d．has been. 原文里那句话是The Verrazano Bridge, which was designed by Othmar Ammann, 为什么这个题目里bridge后面可以加逗号?还有为什么用is?

各位大侠请帮我分析下这个句子
Verrazano,an Italian about whom little is known,sailed into New York Harbour in 1524 and named it Angouleme.
请问 为什么whom后面 不接is little known?而是 little is known?还有为什么此处 不用was 要用 is
little难道在这里的词性是名词？

英语语法
though Verrazano is by no means considered to be a great.
Mrs Ramsay was instructed to plade the money in a cardboard box.这两句中to be a great.和 to plade the money in a cardboard box分别是宾语还是主语补足语?怎样区分宾语和主补的区别呢?

Verrazano,an Italian about whom little is known,这句话要是调整过来应该是an Italian who is known about little,little在这里是副词,把about提前也应该是an Italian about whom is known little,为什么把little给放到whom后面了?请给说说