一个英语句子的分析

should后的部分同为how much 的成分，也就是说“how much pleasure and excitement tourism can afford us should all the cultural differences between hosts and guests be eliminated”中含有两个并列形式的结构，可拆解为：“how much pleasure and excitement tourism can afford us”和“how much should all the cultural differences between hosts and guests be eliminated” (其实这部分用了倒装结构原句可改为how much cultural differences between hosts and guests should be all eliminated)

后面的两并列成分都同时作为“imagine ”的宾语，也即should后做imagine的宾语成分。

而整句可翻译为“我难以想象旅游业能够给我们带来多少愉悦和兴奋，也难以想象有多少存在于主客之间文化差异能被消除”（由于后两者都作imagine的宾语因此如此翻译）

这个should 倒装了 ...can afford us all the cultural differences between hosts and guests （should） be eliminated. 这样不就顺了。其实这个should是可以去掉的