Three promotional materials used by public relations include:

Three promotional materials used by public relations include pamphlets, books and articles. 
The science of building relationships between an organization and its main audiences is called public relations. This branch may sometimes use promotional materials to reach their audience to promote their products and services. 

Hi,

Three promotional materials used by public relations include:
- pamphlets, - books,
- articles

That's true, it's a belief in one god

They made a checks and balance system to equal power within the branches. the "check" meant that one branch would watch one branch and "balance" them if they were too powerful. if you want more info on this, i would just google checks and balance system.