Most of the money for preconvention campaigns for presidential candidates comes from

from the super PAC (special political action committees.)

Explanation:

The major source of campaign financing is the Super PAC, the special political action committees.this organization is allowed by the Supreme Court to spend unlimited amounts of money on their preferred candidate. The money spent by Super PACs is part of a presidential campaign, although it does not represent money spent by the candidate.

radioactive dating, also known as  radioisotope dating  is a process that in  estimating the approximate  age  of  rocks. these data can be analyzed from  the studies dealing with the  decay of the radioactive elements that are present in these rocks. in nature, there are a few types of materials or atoms which are quite unstable and they spontaneously decay or breakdown to form other kinds of atoms.

some women in the middle and upper classes worked as doctors, government officials, or priestesses. both women and men enjoyed a better quality of life the higher they were on the social pyramid. the egyptians believed that their class system created a stable, well-ordered society. each group had its own role to play.