What are molecules x and y in the image

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

Aplant with dark red flowers is crossed with a plant with white flowers. all of the offspring have dark red flowers with white spots. the alleles got flower color in this plant are both dominant both recessive codominant incompletely dominant

Animals have a variety of adaptations,including trachea and gills, which allow this key process to occur. which provides the molecules necessary for cellular respiration and efficient atp synthesis?