Classify each of the following as either a stock or a flow.
a. Myung Park earns $850 per week.
b. Time Warner purchases $100 million in new computer equipment this month.
c. Sally Schmidt has $1,000 in a savings account at a credit union.
d. XYZ, Inc., produces 200 units of output per week.
e. Giorgio Giannelli owns three private jets.
f. General Motors' production declines by 750 autos per month.
g. Russia owes $25 billion to the International Monetary Fund.