When betty uses an idea, a quotation, or section from a source in her writing, how often should she need to cite the source?

Read this excerpt from the grapes of wrath: snub-nosed monsters, raising the dust and sticking theirsnouts into it, straight down the country, across thecountry through fences, through dooryards, and in and outof gullies in straight lineswhich best describes the tone in this passage