Answer:
Geo thermal : Nuclear reactions
Bio mass : plants
Solar : sun rays
Hydro power : Water
Explanation:
Geothermal energy is also used to directly heat individual buildings and to heat multiple buildings with district heating systems. Hot water near the earth's surface is piped into buildings for heat. A district heating system provides heat for most of the buildings in Reykjavik , Iceland.
The major biomass sources currently used are sugar cane and corn to produce bioethanol , and rapeseed for biodiesel production. Other sources are also used such as sunflower seeds, soybean, canola, peanuts, jatropha , coconut and palm oil for biodiesel, and wheat, sugar beet, sweet sorghum and cassava for bioethanol
Conversion of energy from sunlight into electricity
Hydropower or water power is power derived from the energy of falling or fast-running water, which may be harnessed for useful purposes.
The surface layer of the water freezes solid creating a barrier that insulates the ice below so that it keeps a steady temperature usually a few degrees above freezing (32 degrees).
C. Decreased death rate is the answer
The immune system. It produces antibodies which fight the bacteria or virus that caused the infection
