Why should you use an ellipsis

How you think your hometown would look without electricity? explain in one paragraph

While looking at ads on a professional job site, justin saw this job posting: "the employee should have a degree in human behavior and at least 5 years experience in behavioral modifications. we are also looking for an employee who is good at crisis divergence. typically employees will spend a lot of time supporting others."

In a midsummer night dream, the mention of is an allusion to earlier english poetry