<span>1. D dripstone produced by buildup of minerals precipitated from groundwater.
Water drips down from, for example, the roof of a cave and slowly leaves behind mineral deposits which form a shape similar to an icicle 2. D running water cuts small channels into a slope
Rill erosion is formed by soil removal from small streams of running water. They form based on how the water falls down a slope and tend to migrate to already depressed or softer areas of soil.</span>
Birds and bats have homologous limbs because they are both ultimately derived from terrestrial tetrapods, but their flight mechanisms are only analogous, so their wings are examples of functional convergence.
