What part of speech is err?

(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.”)

The balance includes both the fees for service and the shipping charges. is this sentence incomplete or complete?

Complete the sentence. when trying to determine the meaning of an unfamiliar word, you should first replace the unfamiliar word with a synonym that you identified based on the context clues. remove the unfamiliar word from the sentence. think of an antonym for the unfamiliar word. look for context clues that indicate the word's meaning.