我在做toefl tpo 阅读，是 tpo17 的第一篇，有问题不是很懂，请高手指教

我在做toefl tpo 阅读，是 tpo17 的第一篇，有问题不是很懂，请高手指教

The sheer scale of the investment 投资的巨大规模。
it took to begin commercial expansion at sea 这里it是形式主语，to begin后面为真正的主语。
it took to begin commercial expansion at sea 是作为The sheer scale of the investment 的定语。
The sheer scale of the investment it took to begin commercial expansion at sea 翻译为：用于开展海上商业扩张的巨大投资规模
the immensity of the profits that such East-West trade could create 这个句子在整个句子中做宾语，本身优势一个定语从句，that后面的为profits 的定语
整句翻译：用于开展海上商业扩张的巨大投资规模反映出了这种东西方贸易所能创造出的利润无限巨大。

it took the sheer scare of the investiment to begin commercial expansion...这里的it如果没有上下文是说不清楚的。

it took to begin commercial expansion at sea这个分句是定语从句， 前面的The sheer scale of the investment是先行词，省略了作后面定语从句中took的宾语的关系代词which/that。it是形式主语，真正的主语是后面的动词不定式to begin commercial expansion at sea 。如果分成两个句子就是： （1）It took sheer scale of the investment to begin commercial expansion at sea。（2）The sheer scale of the investment reflects the immensity of the profits that such East-West trade could create.
这句话大致的意思是：开始海上贸易扩张需要的投资的规模反映出这样的东西贸易创造巨大利润。