The answer is oxygen
hope it helps!
A) a common ancestor
Homologous structures are structures that are similar in related organisms. There is a basic pattern of bones which can be inherited from a common ancestor
Answer:
A hill is a part of land that rises higher then everything surrounding it its like a little bump in the earth. Mountains have less steep and not as high but a hill will usually have and obvious summit which is its highest point
Probably smaller bodies of water, as less water will heat up and evaporate faster.
