Select the correct answer from each drop-down menu. In an experiment, Dr. Travis examined the effects of calcium intake on osteoporosis, a condition that causes an increased risk of bone fractures. The amount of calcium is what
variable. The risk of bone fractures can be changed by what?
.

By consuming necessary amount of calcium per day.

Explanation:

The amount of calcium is recommended for adults are 1000 mg per day whereas for aged people, it should be 1200 mg per day and for children it becomes 1300 mg per day in order to make the bones stronger and avoid the risk of fracture. The risk of bone fractures can be changed by consuming the recommended amount of calcium through your diet.

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.