Final answer:
When the price of a product drops and there is not enough supply to meet demand, it creates a shortage. When there is an increase in demand but an excess supply, it creates a surplus. When the price of a product rises too high and consumers stop purchasing it, it creates a shortage.
Step-by-step explanation:
When the price of a product has dropped greatly and store owners do not have enough of the item to meet demand, it demonstrates a shortage.
When the demand for a new truck is beginning to increase, but car dealerships still have too many of these trucks on their lots, it demonstrates a surplus.
When the price for a popular holiday toy has risen too high and consumers are not purchasing items in stock on store shelves, it demonstrates a shortage.