These are my last exam questions i need help with, i’m sorry i’m asking for so much, i woke up late today and missed my science exam so now i have to makeup for it and i’m in a hurry, hope someone can help!

Sound waves

It's speed increases

And I'm not sure about the last one. I think maybe density increases but I'm not sure

Explanation:

this is math not biology xd

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.