How do erosion and deposition work together to form sand dunes? 1. Waves cause erosion along coastlines and deposit sand away from the shore. 2. Erosion occurs as surface water carries sediment and the sediment is deposited near oceans and lakes. 3. Glaciers cause erosion through the movement of large chunks of ice, which are deposited and form depressions. 4. Erosion occurs through deflation, and sand that was picked up is deposited against an obstruction.

To answer this question, researchers studied populations of the dusky salamander (desmognathus ochrophaeus) living on different mountain ranges in the southern appalachian mountains. the researchers tested the reproductive isolation of pairs of salamander populations by leaving one male and one female together and later checking the females for the presence of sperm. four mating combinations were tested for each pair of populations (a and b)—two within the same population (female a with male a and female b with male b) and two between populations (female a with male b and female b with male a). the proportion of successful matings for each mating combination was measured. for example, when all the matings of a particular combination were successful, the researchers gave it a value of 1; when none of the matings were successful, they gave it a value of 0. then the researchers calculated an index of reproductive isolation that ranged from 0 (no isolation) to 2 (full isolation). the reproductive isolation value for two populations is the sum of the proportion of successful matings of each type within populations (aa + bb) minus the sum of the proportion of successful matings of each type between populations (ab + ba). the table provides data for the geographic distances and reproductive isolation values for 27 pairs of dusky salamander populations.

When an object is moving away from you while still making a sound, the pitch of the sound is perceived to a. lower b. unchanged c. fluctuating d. higher

Which of the following is situated at the base of the lungs? a. diaphragm. b. larynx. c. bronchi. d. pharynx.