In this task, you will be shown a passage. You need to write a fill-in-the-gap question based on your understanding of the events that might be inferred from the passage. Your question should be answerable based on the passage and only have one correct answer. Show the gap in your question with a _ .

Stunning footage has emerged showing wave-like clouds over the skies of Colorado. The Breckenridge Resort tweeted the video to highlight something known as Kelvin-Helmholtz waves, which can be found all over the solar system, including in Saturn's atmosphere. This beautiful pattern emerges in clouds when two different layers of air in the atmosphere are moving at different speeds. Kelvin-Helmholtz waves are everywhere. From Earth's clouds and ocean surfaces to the atmosphere of Jupiter, these waves have a striking pattern - a series of curled hills moving steadily in one direction. The shape of this pattern has a simple cause. A fast fluid, say wind, moving past a slower one, such as water, naturally creates this wave shape.Pattern created when when two layers of air move at different speedsThese Kelvin-Helmholtz waves are more common than first thoughtCan also be found in Saturn's atmopshere and Earth's magnetosphere
The first paper compared Kelvin-_ waves to what was seen in the solar wind, the second team compared it to what was happening closer to Earth.