Substance of an atom of 2 or more elements

Describe different biomes. what are some adaptations that organisms (plants or animals) must have to live in each biome?

Erosion of the beach is normally a slow process. however, in certain situations, large chunks of shore may wash out to sea. what could cause this to happen?

Students design a model roller-coaster track. they place a rubber ball at the highest point on the track and let it go. the ball rolls along the track pulled only by the force of gravity. eventually, it comes to a stop. which change to the design will result in the ball moving the greatest distance?