Fill in the blanks:
a. When demand is elastic, an increase in price causes quantity demanded to_______________  and total revenue to _______________.
b. When demand is inelastic, a decrease in price causes quantity demanded to and_______________  total revenue to _______________.
c. When demand is unitary elastic, an increase in price causes quantity demanded to _______________and total revenue to _______________.
d. If price falls and total revenue falls, demand must be _______________.
e. If price rises and total revenue stays the same, demand must be _______________.
f. If price rises and total revenue rises, demand must be _______________.