Two stars orbit each other in a(n) star system.
a.
binary
c.
single
b.
closed
d.
individual

Correct A). Binary

A binary star is a star system that consists of two stars that are revolving around their common center. These are close to each other and the gravitational force causes them to revolve around each other. The most common binary system are binary stars and binary asteroid.

Hence, the correct answer would be option A.

1. a tropical dry forest carries out more rapid nutrient cycling

clumped distribution, because you'de have all of the population gathered in a relatively small are.

it's the most common because it provides protection and a mate for reproduction

example: humans, seeweed, cattles, etc.