The best answer is (1)
Fossil fuels are commercially available as an energy source.
They are very easy to find. More and more extractions of fossil fuels is going on everyday. With advancement in science and technology, the refineries and extraction procedures have improved a lot. This makes their availability even better.
Fossil fuels are also easily combustible. Most combustion engines need to be powered with little amount of fuel to produce large amount of energy. Very large amounts of electricity can be generated from fossil fuels.
Carbon shares 4 electrons to complete its valence shell
In the cells with nucleus, as in eukaryotes, the cell cycle is also divided into three periods which are: Interphase- the mitotic (M) phase, and cytokinesis. During interphase the cell growth accumulating nutrients needed for mitosis preparing it for cell division and duplicating its DNA
Viruses are made up of DNA
