I want to test the ability of students to read a passage and answer questions about it. Could you please come up with a good question for the passage "In the 1970s, computer engineers at research institutions throughout the United States began to link their computers together using telecommunications technology. The effort was funded by ARPA (now DARPA), and the computer network that resulted was called the ARPANET. The technologies that made the Arpanet possible spread and evolved."?
A loop in a chain is called a?