An important challenge to traditional (pre-1860) ideas about species was the observation that seemingly dissimilar organisms, such as hummingbirds, humans, and whales, have similar skeletal structures. this most directly suggested to biologists that

i do believe that the correct answer is   (technical reasoning); luck

explanation:

i believe

clean air is essential for health and survival

clean air provides nitrogen gas for plant respiration

clean air supplies oxygen that enables living organisms to breathe

hope this

i am brianly

sorry if this doesn't

south, because if you took a map you would see texas is directly in the middle of east and west, but it is also downwards towards mexico, therefore it is south