Planet A is an inner planet with no moon and hardly any atmosphere. Planet B is an inner planet with no moon but with a dense atmosphere. Which pair of planets is being described? A.
Mars and Venus
B.
Mercury and Earth
C.
Mercury and Venus
D.
Mars and Earth

The idea that desirable traits can be bred into human beings and undesirable ones can be bred out is known as:

The persian wars started when emperor darius i began an invasion of greece. what caused darius to decide to attack greece? a. greek pirates had raided persia's merchant ships and coastal towns. b. greek armies had attacked and taken over land that belonged to persia. c. greek city-states had supported rebellions in the persian empire. d. greek leaders had declared independence from the persian empire.

What is the name of the large desert that runs across north africa