A, An ancestor of whales had legs. Hope i helped! :D
The primarily use of coal is mostly used for electricity generation, steel production, cement manufacturing, and as liquid fuel.
Advantages: it helps produce electricity, coal energy is affordable energy source because coal's stable price compared to other fuels sources, coal is easy to burn, coal produces high energy upon combustion, coal energy is inexpensive, coal is abundant, coal energy is a reliable energy source.
Disadvantages: coal energy produces large amount of carbon dioxide which leads to global warming and climate change, the burning of coal is not environmental friendly because it produces harmful byproducts and gas emission such as sulfur dioxide, carbon dioxide and nitrogen oxide that causes pollution to the environment including acid rain, coal energy is nonrenewable energy source, coal is fast depleting because we dont consume too much of it, coal mining ruins the environment and puts the lives or people especially the coal miners in danger. <span />
As water vapor rises in the atmosphere, it cools and changes into liquid cloud droplets in a process called condensation
I believe the answer is Unicellular Euglena.
Euglena are unicellular organisms classified into the kingdom protista, and the phylum euglenophyta. All euglena have chloroplast and can make their own food by photosynthesis. They are considered to have both plant and animal features. The mobility of Euglena also allows for hunting capability, because of this adaptation.
