Earth possesses few visible craters and the Moon possesses many. This is because
a. Earth formed later than the Moon and, therefore hasn't encountered as many meteoroids.
b. the Moon doesn't have an atmosphere that could burn up many of the meteorites before impacting.
c. erosion and plate tectonics have slowly removed evidence of past cratering on Earth.
d. Earth formed later than the Moon and, therefore hasn't encountered as many meteoroids; the Moon doesn't have an atmosphere that could burn up many of the meteorites before impacting; and erosion and plate tectonics have slowly removed evidence of past cratering on Earth.
e. the Moon doesn't have an atmosphere that could burn up many of the meteorites before impacting and erosion and plate tectonics have slowly removed evidence of past cratering on Earth.
Question 2
Which of these gases is most responsible for the greenhouse effect on Earth?
a. oxygen (O2)
b. nitrogen (N2)
c. carbon dioxide (CO2)
d. ozone (O3)
e. ammonia (NH3)