Which of the following words is opposite in meaning to careless? dramatically harmful cautious obvious

After taking notes carefully and studying freqently, derek not only passed the test, select the word group below that best completes the sentence in parallel structure. and he got 100% but he scores well on classwork but he also scored the highest in the class and he was also scoring the best he ever had

(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.”)

In researching his history report about the civil war, why is ariq most likely to use secondary data than primary data?