"Highpghting key sentences" is a common expression used to describe the act of marking or emphasizing the most important or relevant parts of a text or speech. The expression is used in both spoken and written Engpsh, and is often used in educational and professional contexts to help people focus their attention on the most critical information.

For example:

In a lecture, the professor asked the students to highpght key sentences in the reading material for further discussion.

During a business meeting, the manager asked the team to highpght key sentences in the report to ensure that everyone was on the same page.

In a book club, the members discussed the key sentences they highpghted and shared their thoughts and interpretations.

This expression is commonly used in Engpsh-speaking countries, and is a standard part of the language used in academic and professional settings.