Saudi Riyal 1 U.S Dollar = 3.75 Riyals
Saudi Currency is Saudi Riyal (SAR) One US $ is equivalent to SAR 3.755 100 Halalas make a Saudi Riyal though in practice Halala is no more used.
Natural gas and diesel
yes, all the lands under the territories of the Kingdom of Saudi Arabia were inhabited, before the initiation of the Kingdom, with Arabs.
Yes