Metaphor; its showing how that rack was moving alot-something like how a teeter totter would look had someone been playing on it. it was comparing the rack to a teeter totter
Answer:
Our restless Earth is always changing. Tectonic plates drift, the crust quakes, and volcanoes erupt. Air pressure falls, storms form, and precipitation results. Learn how these powerful forces shape our air, land, water, and weather—and constantly transform our planet. Explore how our response to Earth's changes will impact our future on Earth and discover how your choices impact our future Earth.
Is kenning part for the word also