What is the present perfect form of the verb to be. he _ a businessman for many years

(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.”)

"and these i address to all females that would be married, or are already so; not that i suppose their sex more faulty than the other, and most to want advice, for i assure [women], upon my honour, i believe the quite contrary; but the reason is, because i esteem them better disposed to receive and practice it, and therefore am willing to begin, where i may promise myself the best success." this statement from franklin's "rules and maxims for promoting matrimonial happiness" best demonstrates his use of criticism to argue his point his use of common sense to appeal to women his use of flattery to gain women's attention his use of facts to prove his point

Read the hypothesis below and answer the question that follows. playing video games will improve individual spatial skills. what is the dependent variable in the experiment? a. playing video games b. type of subjects c. type of video game d. spatial skills