Longitudinal waves compress the medium they travel though. one example of a longitudinal wave is a

Waves in compressed string

Explanation:

Longitudinal waves are waves in which the vibration of the medium is going parallel to the direction of the waves produced by the medium.

Longitudinal wave can occur in compressed string. A compressed string displaced horizontally will transmit wave in the same horizontal direction. That's why they are longitudinal waves.

The real monsters of Maple Street are the people who live there. The aliens have come to expect that people will behave like monsters when faced with something that scares them. They knew that when they turned the power off, the citizens of Maple Street would blame each other and destroy themselves.

Hope this helps!!!