Describe one way the student could change the intensity of light reaching
the pondweed.

The student could move the lamp further away from the pondweed, for low light intensity. For high intensity, the student should move them lamp closer to the pondweed.

Explanation:

Hope this helps!

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.