奇妙用法，请高手解释--搬板凳等着呢：）谢谢

1.When the Cold War ended, the project lost its original purpose, so another purpose was quickly grafted onto the project, that of  conducting limited-gravity experiments, even though such experiments can be done in an alternative way.

2. The format of newspaper stories, on the other hand, leads readers to pursue details of stories headed by the most important facts and so has the opposite effect on regular readers—that of maintaining the expectation of careful discussion of public issues

问题：1。请问这两个that 分别指代什么？

           2. that of +doing 这种形式怎么理解？

           3. 这两个句子中蓝色部分。So 引导的成分在这里怎么理解？

           4. 我没想到的请各位江湖高手指点：

 多谢！！！！！多谢！！！！

1。that of 在这里是联系代词的副词用法，是用来修饰前一个从句的。第一个that of修饰的是以purpose为中心的从句，第二个修饰的是以effect为中心的从句。

2。见上

3。两个so都可以理解为所以的意思

4。没精力研究你还有什么想不到的