Which of these are vestigial structures? A. the sharp spines of a cactus
B. the wings of a butterfly
C. the hip bones found in some spees of snake
D. the thick fur and layer of fat of some mammals in cold climates

Anitrogen atom and an oxygen atom combine chemically to form nitric oxide. what is nitric oxide?

Write the balanced chemical reaction for the formation of fe2(so4)3 from fe2o3 and so3 and determine how many moles of fe2(so4)3 are formed when 12.7 mol of so3 are reacted.

How are casts formed by decaying organisms? organisms turn into rock over time. organisms leave carbon residue on a rock. organisms leave impressions in sediment that hardens into rock. impressions left by organisms are filled in with sediment that hardens into rock.