Mark the statement if it correctly describes human interaction with the environment.
a.
since ancient times, people have used waterways for transportation.
b.
when natural waterways are too difficult to navigate, people sometimes dig canals to provide a better means of transportation.
c.
very few groups of people have found ways to use rough or rapid rivers for transportation or irrigation.
d.
canals are man-made waterways that change the natural landscape to meet human needs.

regarding the law, the 15th amendment was specifically designed thinking in the rights of black free men.

even though ratified on february 3, 1870, the promise of the 15th amendment would not be fully applied for a long time.poll taxes and literacy tests would allow southern states disenfranchise african americans. only in 1965 the voting rights for african americans would be actually able to vote in the south.

in 1965, president johnson signed the voting rights act, which aimed to overcome legal barriers that prevented african americans from voting as it was guaranteed by the 15th amendment to the u.s. constitution.

b. martin luther king jr. wrote and spoke "i have a dream"

explanation:

i know this 100 percent is correct   b. is the best one. < 3