Phylogeny refers to
a. the evolutionary history of a group of related organisms.
b. a group of organisms that includes an ancestor and all of its descendants.
c. darwin’s method to classify organisms.
d. all of the above

The answer is c because phylogeny is being described in every one of these answer choices.

The speed of  sound:   sound travels  at different speeds depending on what it istraveling through. of the three mediums (gas, liquid, and solid)  sound waves travel the slowest through  gases, faster  through  liquids, and fastest  through  solids.