7 While visiting a historical fort, John watched a demonstration of the firing of an old cannon from a distance of 50 m. When
the cannon fired, John heard a loud boom a second later. What was the medium that allowed the sound waves to reach
John?
A the ears
B the cannon
C the air
D the ground

when atoms of different types of elements join together, they make molecules called compounds. water consists of compound molecules made up of 2 hydrogen atoms and 1 oxygen atom. this is why it's called h2o. water will always have 2 times the number of hydrogen atoms as oxygen atoms.

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.

a. to encourage apoptosis