1Simply there are people in Nigeria who cannot travel to the Smithsonian Institution to see that part of their history and culture represented by the Benin Bronzes.
主干主语：people in Nigeria；谓语：there are（存在句）；定语从句：who cannot travel... 修饰 people
结构there be 存在句，主语 people 后接 in Nigeria 介词短语作后置定语；who 引导定语从句修饰 people，从句内 to see... 为不定式作目的状语；see 的宾语是 that part of their history and culture，其后 represented by the Benin Bronzes 为过去分词短语作后置定语，修饰 that part，构成'被贝宁青铜器所代表的那部分历史文化'。
译文很简单，尼日利亚国内有些人无法远赴史密森学会，去瞻仰那部分由贝宁青铜器所代表的、属于他们自己的历史与文化。
考点过去分词短语 represented by... 作后置定语，相当于定语从句 which is represented by...，阅读时注意将其还原到被修饰词之前 · there be 句型中真正主语在 be 动词之后，定语从句 who... 修饰的是 people 而非 Nigeria
2Having said that, I do feel that whatever artifacts find their way to public museum should, in fact, be sanctioned as having been obtained on loan, legally purchased or obtained by treaty.
主干主语：I；谓语：do feel；宾语：that 引导的宾语从句（从句主干：whatever artifacts... should be sanctioned）
结构句首 Having said that 为现在分词完成式作让步状语，相当于 Although I have said that；do feel 中 do 表强调；that 宾语从句内，whatever artifacts find their way to public museums 为 whatever 引导的主语从句（whatever 兼作 artifacts 的定语）；should be sanctioned as 后接动名词完成被动式 having been obtained，表示'被认定为是以……方式获得的'。
译文话虽如此，我确实认为：凡是流入公共博物馆的文物，都必须被认定为是通过租借、合法购买或条约途径获得的。
考点whatever 引导主语从句时相当于 any...that，兼具引导词和限定词双重功能 · having been obtained 为动名词完成被动式，作介词 as 的宾语，强调'获得'这一动作先于'认定'发生
3What intrinsic factors make the West a suitable home for these artifacts but preclude them from being preserved and displayed by their countries of origin?
主干主语：What intrinsic factors；谓语：make... but preclude...（并列谓语）；宾语：the West / them
结构特殊疑问句，what 作定语修饰 intrinsic factors，整个名词短语作主语；谓语由 but 连接的两个动词构成：make（make+宾语+宾补 a suitable home）和 preclude（preclude sb from doing sth '使某人无法做某事'）；from 后接动名词被动式 being preserved and displayed，by 引出动作施事者。
译文究竟是哪些内在因素，让西方成为这些文物的适宜归宿，却又使其来源国无法对它们加以保存和展示？
考点preclude sb from doing sth 为固定搭配'阻止/使某人无法做某事'，from 后须接动名词 · but 在此连接并列谓语而非并列句，前后主语一致（均为 factors），注意不要把 preclude 误当作另一分句