A.
43. I'm going to buy a hybrid car because of its lower gas consumption compared to other cars.
44. China produces the most wind power in the world.
45. Solar panels are quite expensive to install, but you can save money on electricity in the long run.

B.
46. This backpack has small solar panels on it, and you can actually use them to charge your phone.
47. Nuclear power is a clean and efficient way of producing electricity, but it may also be dangerous.

C.

• The most popular renewable energy source: Solar power is the most popular renewable energy source.
• The country that produces the most hydroelectricity: Canada produces the most hydroelectricity.
• The fastest-growing renewable energy source: Wind power is the fastest-growing renewable energy source.
• The most efficient renewable energy source: Geothermal power is the most efficient renewable energy source.