Is "I love her work, it's amazing" a complex sentence

(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.”)

Which lines from the speech best supports this topic sentence? and as we walk, we must make the pledge that we shall always march ahead. we cannot turn back. there are those who are asking the devotees of civil rights, "when will you be satisfied? " and they have come to realize that their freedom is inextricably bound to our freedom. we cannot walk alone. we refuse to believe that there are insufficient funds in the great vaults of opportunity of this nation. and so we've come to cash this check, a check that will give us upon demand the riches of freedom and the security of justice. and so let freedom ring from the prodigious hilltops of new hampshire. let freedom ring from the mighty mountains of new york. let freedom ring from the heightening alleghenies of pennsylvania.

Read the sentence. bose ikard, a former slave, managed one of the largest thriving ranches in texas. which is the verb of the sentence? managed thriving a former slave bose ikard