The answer is A. a light wave
C and D both need water as a medium and sound needs air to vibrate in order to travel. light, on the other hand, does not need a medium
Answer:
Skeleton and the skeletal system
Explanation:
Changes in groups of organisms over time produce variations in a population. This relates to both macroevolution and microevolution.
These are evolutions within a small group or a population and across the whole species.
A plant cell is rectangular, while an animal cell is circular.
B: 2.3 grams to 9.8 grams