Question

which characteristic do venus and earth share? same direction of rotation similar size, mass, and density slow revolution period around the sun atmosphere composed only of carbon dioxide

Explanation:

Venus and Earth are often called "sister planets" because they have similar size, mass, and density. Venus rotates in the opposite direction to Earth. Venus has a relatively fast revolution period around the Sun compared to some outer planets. Earth's atmosphere is not composed only of carbon dioxide (it has nitrogen, oxygen, etc. as major components).

Answer:

similar size, mass, and density