What are the so-called greenhouse gases that trap heat?
a) carbon dioxide, methane, nitrous oxide, ozone, chlorofluorocarbons
b) oxygen, water vapor, black carbon, carbon dioxide
c) hydrogen, nitrogen, sulfur dioxide, oxygen
d) carbon dioxide, methane, oxygen, ozone
e) ozone, smog, nitrous oxide, aerosols
Question 2
Why are spring tides highest when the Moon is near perigee?
a) The Moon is moving fastest in its orbit at that time
b) The Moon is farther from Earth, so gravitational force is greater
c) The difference between solar and lunar tides is maximum at this time
d) The Moon and Sun are lined up
e) The Moon is closer to the Earth, so gravitational force is greater
