What does the stroma of the chloroplast in higher plants contain?

Why is $RuBisCo$ enzyme the most abundant enzyme in the world?

Why is the $RuBisCo$ enzyme more appropriately called $RuBP$ Carboxylase-Oxygenase and what important role does it play in photosynthesis?

How many $ATP$ and $NADPH$ molecules will be required to make one molecule of glucose in the $C_3$ pathway?

$3 CO_{2} + 9 ATP + 6 NADPH + \text{water} \rightarrow \text{glyceraldehyde 3-phosphate} + 9 ADP + 6 NADP^{+} + 8 \Pi$. Analyse the above reaction and answer the following questions:
$(a)$ How many molecules of $ATP$ and $NADPH$ are required to fix one molecule of $CO_{2}$?
$(b)$ Where in the chloroplast does this process occur?

Provide the full names for the following abbreviations:
$(1)$ $RuBisCO$
$(2)$ $KOH$