老师你好！
2020年全国新高考考试卷I阅读理解题C里第二段开头几句是如此的:
His visit,however,ended up involving a lot more than that. Hence thisbook,Chasing the sea:Lost Among the Ghosts of Empire in Central Asia,whichtalks about a road trip from Tashkent to Karakalpakstan, where millions oflives have been destroyed by the slow drying up of the sea.It is the story ofan American travelling to a strange land, and of the people he meets on hisway.
我对上面第二句话从Hence this book，.......到where millions oflives have been destroyed by the slow drying up of the sea.的句子结构理解不透，不了解主干句在哪儿？请老师指点句法剖析。谢谢！
Hence this book, Chasing the sea: Lost Among the Ghosts of Empire in Central Asia, which talks about a road trip from Tashkent to Karakalpakstan, where millions of lives have been destroyed by the slow drying up of the sea.
问题就在黑体部分。this book 是主语，这里省略了谓语动词。“连接副词” hence， 有时依据上文引出一个名词短语，单独成句。本句在 this book 之前省略了一个不及物动词（比如 appeared，不可以放在后面，由于后面是书名作同位语）。又如：
Hence Foer's book, which is published by Penguin this month.
于是弗尔的新书应运而生，这本著作将于本月由企鹅出版社出版。
Hence the need for government action.
因此，需要政府采取一些手段。
We suspect they are trying to hide something, hence the need for an independent inquiry.
大家怀疑他们在企图隐瞒啥事，因此有必要进行独立调查。
《牛津词典》
Hence this book，Chasing the Sea: Lost Among the Ghosts of Empire in Central Asia，which talks about a road trip from Tashkent to Karakalpakstan, where millions of lives have been destroyed by the slow drying up of the sea.
【翻译】因此便有了这本书：《追逐大海：迷失在中亚帝国的幽灵之中》，它讲述了从塔什干到卡拉卡尔帕克斯坦的一次公路之旅，在那里，因为海水的缓慢干涸，数百万人的生命遭受灭顶之灾。
剖析：句中hence后直接跟了省略了谓语动词的名词this book，表示一种推理性结果；Chasing the Sea：Lost Among the Ghosts of Empire in Central Asia 是 this book 的同位语；which 是关系代词，引导非限制性定语从句，修饰此书（书名）；where 是关系副词，引导非限制性定语从句，修饰Karakalpakstan。
