A researcher did an experiment in which he had one group of people drink a liter of coffee in an hour and a control group of people drink a liter of water within the same amount of time. He then measured their urine output over the course of the next two hours. Both groups produced an average of 250 ml of urine per hour over that time period. He concluded that the coffee itself had no effect on urine output. Given his results, what else should he measure to identify the effects of coffee drinking?

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.

i'm guessing this is from edg enuity so the answers would be, from top to bottom,

theodor schwann

matthias schleiden

robert hooke

rudolph virchow

anton van leeuwenhoek