Choose the best answer for why Six Flags commissioned a study on the safety of theme parks. a.
They need to convince people that their rides are safe so they will ride them.
b.
They knew the government was going to try to regulate them.
c.
They had nothing better to do with their time and money.
d.
They wanted to prove that roller coasters are the most amazing invention ever!

(1) fire extended humans’ geographical boundaries by allowing them to travel into regions that were previously too cold to explore. (2) it also kept predators away, allowing early humans to sleep securely. (3) fire, in fact, has been a significant factor in human development and progress in many ways. (4) other obvious benefits of fire are its uses in cooking and in hunting. (5) probably even more important, however, is that learning to control fire allowed people to change the very rhythm of their lives. (6) before fire, the human daily cycle coincided with the rising and setting of the sun. (7) with fire, though, humans gained time to think and talk about the day’s events and to prepare strategies for coping with tomorrow. the sentence that expresses the main idea is: (type the number of the sentence. then click “go.”)