___ bonds form between complimentary base pairs and ___ bonds form between the sugar and the phosphate molecules in the "backbone" of the DNA molecule.

A. covalent; hydrogen
B. hydrogen; ionic
C. hydrogen; covalent
D. ionic; covalent

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.