The law of gravitation is used to derive kepler’s law of planetary motion.

The answer on e2020 is 3rd

Explanation:

the answer is "a.) well–developed vascular system."

explanation:

sheep is a herbivore animal whereas grasshopper belongs to the class chordates but both of them feed on greens.  

if grasshopper and sheep feeding on a pasture land, i do not think both of them will have any impact on each other. however, the number of the species can make difference. since sheep feed on greens, there is a possibility there left no pasture land for the grasshoppers or they may get extinct.