Which action is an example of direct democracy?

In the United States, where there is no direct democracy at the federal level, in more than half of the states (and many municipalities) citizens promote the voting of actions, and most states have mechanisms to encourage initiatives or referendums. In making decisions, citizens can interact with those responsible for administration in decision-making.

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.

the main objectives of the progressive movement were eliminating problems caused by industrialization, urbanization, immigration, and political corruption.