Question

question 9
why is there reluctance to eliminate fossil fuels as an energy source?
a there are no other sources of energy.
b they are relatively cheap to obtain.
c other methods of energy production are not as efficient.
d they are unlimited in supply.
e all of these.

question 10
greenhouse gasses block:
a carbon dioxide escape from the earth
b oxygen that escapes from the earth
c heat that escapes from the earth
d uv wavelengths from reaching earths surface
e uv wavelengths from escape from the earth

Explanation:

• Question 9:
• Option A is incorrect as there are other energy sources like solar, wind, hydro - power.
• Option B is correct. Fossil fuels are relatively cheap to obtain compared to some renewable energy sources in terms of current infrastructure and extraction costs.
• Option C is incorrect. Many renewable energy methods like hydro - power (in suitable locations) can be very efficient.
• Option D is incorrect. Fossil fuels are non - renewable and have a limited supply.
• Option E is incorrect since not all options are correct.
• Question 10:
• Greenhouse gases (e.g., carbon dioxide, methane) trap heat (long - wave radiation) that would otherwise escape from the Earth.
• Option A: Carbon dioxide is a greenhouse gas, but the key is that greenhouse gases block heat escape, not just carbon dioxide escape.
• Option B: Oxygen is not a greenhouse gas in the context of heat trapping.
• Option C: This is correct as greenhouse gases block heat (infra - red radiation) that escapes from the Earth.
• Option D: Ozone (not a typical greenhouse gas in the main sense here) blocks UV wavelengths from reaching the Earth's surface to some extent, but that's not the role of greenhouse gases.
• Option E: UV wavelengths do not escape from the Earth in the same way heat (infra - red) does, and this is not the function of greenhouse gases.

Answer:

Question 9: B. They are relatively cheap to obtain.
Question 10: C. Heat that escapes from the Earth.