What is a pure substance like carbon .?

Ineed the definitions of all of these words nasap i will give 1o points to whoever awnsers

In the diagram below, the northern hemisphere would be in what season at position a a.fall b. winter c.summer d.spring

During the winter, this species of fox has white fur, but in the summer, it has brown fur. what environmental change may have lead to this fox's fur color? snow cover increase in sun's brightness volcanic eruption global warming