Which sentence is the best example of atopic sentence in a paragraph about pet ownership?

young dogs need hours of training.

owners need to set aside time to bond with the dog.

veterinary visits are important to maintain a dog’s health.

adopting a pet dog is a big responsibility.

(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 type of conflict is shaping susan’s development

In mending wall, what is most likely the author’s intent in the following lines to describe boulders? and some are loaves and some so nearly balls we have to use a spell to make them balance