The book is largely based on secondary sources.

这本书的素材来源很大程度上是二手的。

So that's a secondary source. In your research, in the paper you're writing, you may cite or quote both primary and secondary sources.

因此，这是一个第二来源。在你的研究中，在你所写的论文中，你可以同时引用或引述主要和次要来源。

A secondary source could be a book written on Beethoven where the author has written a paragraph about Beethoven's favorite foods.

第二手资料可能是一本关于贝多芬的书，作者写了一段关于贝多芬最喜欢的食物。

The happiness that is derived from some secondary source is never very deep.

来自次要来源的快乐永远不会很深。

Find your evidence from not only secondary sources (text books, etc. , but from primary sources as well.)

找到你的证据不只是从次要来源（教科书等）。)，但也来自主要来源。

Much of what we do know, comes from excavated inscriptions from Phoenician cities and snippets from secondary sources, written after the decline of the Phoenician cities.

我们所知道的大部分内容都来自于腓尼基城市出土的铭文，以及在腓尼基城市衰落后留下的二手资料片段。

Primary documents, and primary sources. Let's explain these terms with secondary sources. Let's say you're doing a research paper on Beethoven and you're researching what his diet was, what he ate.

主要文件，和主要来源。让我们用二级来源来解释这些术语。假设你在做一篇关于贝多芬的研究论文，你在研究他的饮食，他吃了什么。