In 1665, robert hooke, an english scientist, published his book micrographia, in which he described that pieces of cork viewed under a microscope presented small cavities, similar to pores and filled with air. based on knowledge discovered later on, what do you think those cavities were composed of? what is the historical importance of this observation?

Arational expression has been simplified below. (x-5) (x+1)/3(x+1) = x-5/3 for what values of x are the two expressions equal

How does the molecular clock work? a. it analyzes the brain functionality of two different species.b. it examines and compares the physical characteristics of two different species.c. it illustrates relationships between two different species.d. it compares the number of mutations that exist in the dna of two different species.

Johnny rode his bike to a friend's house 4 blocks down the street in his neighborhood. he immediately rode back home once he realized his friend was not able to play. what was his displacement for the total bike ride? how did you determine this? what could we use as a reference point to determine he was in motion during his bike ride? why can you use it as a reference point