<span>In many plants, stomata are found only on
the lower surface of the leaf. The most likely explanation for this fact
is that water loss would be less on the shaded lower surface than in
direct sun. </span>
Eight point about China Rose.
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.
Calcium provides strength as a element, though it is present as calcium chloride on the exoskeletons.