What kind of substances tend to be acidic and what kind of substances tend to be alkaline?

Substances

0 (most acidic)Hydrochloric acid (HCl)

1Stomach acid

2Lemon juice

3Cola, beer, vinegar.

Examples of alkaline are:sodium hydroxide, potassium hydroxide, calcium hydroxide, magnesium hydroxide etc

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.