What do you think the speaker means when he says, “Nature’s first green is gold”? in nothing gold can stay

(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.”)

What does"after getting my report card i knew it was time to hit the books mean

Aids is growing fastest in the poorest countries of africa. these nations don’t have enough doctors, medical labs, or money for medicine. a recent study showed that only a small percentage of hiv-infected children in africa are getting any medical treatment at all. what central idea is emphasized in both sources? the hiv/aids epidemic in africa is serious. the hiv/aids epidemic in south africa is serious. the hiv/aids epidemic among african children is serious. the hiv/aids epidemic among south african children is serious