A big factory has been built in this area _____ such goods for people…

不定式 to 表目的
工厂被建在这块区域的目的是为了给整个国家人民制造这种物品。
我给你找的不定式to的用法
第2 第（6）的第①就是我所说的不定式 to 表目的
其他我也建议你看一下，好以后更容易做这类问题。

1．不定式的形式：（以动词write为例）
否定式：not + (to) do
（1）一般式：不定式的一般式所表示的动作与谓语动词动作同时发生或发生在谓语动词动作之后，
例如：
I'm glad to meet you.
He seems to know a lot.
We plan to pay a visit.
He wants to be an artist.
The patient asked to be operated on at once.
The teacher ordered the work to be done.
（2）进行式：不定式的进行式所表示的动作与谓语动词动作同时发生，例如：
The boy pretended to be working hard.
He seems to be reading in his room.
（3）完成式：不定式的完成式表示的动作发生在谓语动词动作之前，例如：
I regretted to have told a lie.
I happened to have seen the film.
He is pleased to have met his friend.
2．不定式的句法功能：
（1）作主语：
To finish the work in ten minutes is very hard.
To lose your heart means failure.
动词不定式短语作主语时，常用it作形式主语，真正的主语不定式置于句后，例如上面两句可用如下形式：
It is very hard to finish the work in ten minutes.