Lactobacillus is a bacteria that lives inside humans. These bacteria live on the nutrients from our bodies. They help to keep our gut clean and healthy. S. typhi is a bacteria that enters our bodies through contaminated food. This bacteria causes infections in the body. Based on this information, which two statements about the association between these bacteria and humans are true?
Lactobacillus shares a parasitic relationship with humans.
S. typhi shares a parasitic relationship with humans.
Lactobacillus and S. typhi have no relationship with humans.
S. typhi shares a mutualistic relationship with humans.
Lactobacillus shares a mutualistic relationship with humans.

S. typhi shares a parasitic relationship with humans

Lactobacillus shares a mutual relationship with humans

Explanation:

S typhi causes infections, which is negative. It feeds off the body but produces no benefit, it harms. Therefore it is a parasite.

Lacto bacteria feed off of food, which benefits itself, but on the other hand aides in digestion and does not harm the human. Both sides are benefited. So the relationship is mutual. No harm done, both prosper.

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.