Cells A and B receive the same high levels of stimulation, but Cell A shows a lower level of activity relative to Cell B. A likely explanation for this fact is that Cell A

Cell A is laterally being inhibited by other neighbouring cells.

Explanation:

Cell A showing lower activity compare to cell B despite both having high simulation is because Cell A is surrounded by neighbouring cells and these neighbouring cells hinder the action potential of cell A through their numerous activity they perform around cell A.

Therefore they restrain the activities of cell A.

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.