Which inventor raced against nikola tesla and others to devised the radio, a system of transmitters and receivers to send messages through the air without wires? a. alexander graham bell b. samuel morse c. thomas edison d. guglielmo marconi

Who was marshall mcluhan and what did he have to do with communication theory?

Why was the treaty of versailles harsh on germany?

How did the invention of the cotton gin affect slave labor in the united states? a. there was a forced migration of slaves from the south to the north. b. slave-owning cotton planters were gradually forced to sell their plantations. c. more slaves were purchased to work on cotton plantations in the south. d. the reduced need for labor on cotton plantations led to a decline in slavery. e. slaves were moved from cotton plantations to sugar plantations.