Final answer:
The impact of an underlined phrase on the meaning of a sentence can vary in writing.
Step-by-step explanation:
In writing, the impact of an underlined phrase on the meaning of a sentence can vary. It could convey necessary information that is essential to the sentence's meaning, or it could provide context, set the tone, or indicate a new idea or transition in the paragraph. It could also help eliminate unnecessary words or phrases. The effect depends on the specific sentence and context in which the phrase is used.