un caballo negro de antepasados desconocidos fue apareado con cierto numero de yeguas de color rojo deraza pura, estos apareamientos dieron 20 descendientes de colo rojo y 25 de color negros

here is the answer

water, ice, acids, salts, plants, animals, and changes in temperature are all agents of weathering. weathering is the breaking down or dissolving of rocks and minerals on earths surface. once a rock has been broken down, a process called erosion transports the bits of rock and minerals away.