Final answer:
Saying no is not an example of how students waste time; it is associated with setting boundaries and managing time effectively, which is essential for academic success and avoiding distractions.
Step-by-step explanation:
The question asks which activity is not an example of how students waste time. When evaluating the options, e-mailing, social networking, and unscheduled visiting could be considered time-wasters, especially if they are done excessively or at inappropriate times, such as during class. However, saying no is often associated with setting boundaries and managing one's time effectively, not with wasting time. Therefore, the correct answer is that saying no is not an example of how students waste time.
In support of this, setting limits by saying no can help a student focus on their priorities, such as attending class, completing homework, or studying for exams, without being distracted by less important or unplanned activities. This approach aligns with the idea that students should put away their phones and other electronic devices during class to avoid being distracted by emails, social media, or games, as such distractions can lead to lower grades according to research. By saying no to time-wasting activities, students can enhance their academic performance and productivity.