What river separates mexico from the united states?

Rio Grande

Explanation:

Rio Grande, Spanish Río Grande del Norte, or (in Mexico) Río Bravo, or Río Bravo del Norte, fifth longest river of North America, and the 20th longest in the world, forming the border between the U.S. state of Texas and Mexico.

the use of electrical signals that transit messages is know as

the declaration states, “we hold these truths to be self-evident, that all men are created equal, that they are endowed by their creator with certain unalienable rights, that among these are life, liberty, and the pursuit of happiness….”