Those elements are:
sulphur
chlorine
argon
neon
carbon
oxygen
helium
silicon
calcium
hydrogen
nitrogen
sodium
fluorine
lithium
aluminum
9 of these elements were known during BCE periods. The knowledge of these basic elements is enough for humanity to start the industrial revolutions by leveraging and combining one elements with another as a catalyze to be included either as ingredient of the products or to speed up the production process.
<span><span> </span>Catholic Church's religious austerity.</span>
The telegraph perhaps one of the most effective technologies used during the Civil War. It allowed commanders to instantly communicate with each other and provide almost real time information about battle results, enemy troop movements, unit locations etc ...
The answer to 1 is d. The answer to 2 is a.