Check out the image of earth. the northern hemisphere is found above the equator (points a and b) and the southern hemisphere is located below the equator (points c and d). here it is warmer in summer (c) than in winter (a), because in summer

a)
the days are longer.

b)
the earth is closer to the sun.

c)
point c gets more direct sunlight.

d)
the southern hemisphere is tilted away from the sun.

relationships play a major role in a human's emotional and mental wellbeing. healthy relationships with the people around you are even linked to a smaller production of cortisol, a stress hormone.

the cladogram shown here shows similarities and differences among several classes of vertebrates. anatomically, the four have limb structure as their common ancestor. we might separate the mammals from the other three classes because they a) divergent; do not lay eggs b) identical; are warm-blooded c) varied; a four chambered heart d) homologous; have mammary glands