TSA CBT Practice Test

The choice of "quickly running" as an example of a phrase is correct because it consists of a group of words that express a single idea but does not form a complete thought or sentence. This combination includes an adverb ("quickly") and a verb ("running"), which together convey a concept related to action but lack a subject and do not stand alone as a complete sentence. In contrast, the other options represent complete thoughts or sentences. "She is running" contains a subject and a predicate, making it a complete sentence. "The dog barked" also has a subject and a verb, qualifying it as a complete thought. Lastly, "Running is fun" features a subject ("Running") and a predicate ("is fun"), thereby also forming a full sentence. Therefore, "quickly running" best fits the criteria for a phrase, while the others illustrate complete sentences.