Final answer:
Goods and services with highly inelastic demand curves include necessities like life-saving drugs and gasoline. These are products that consumers will continue to buy, even with price changes, due to the lack of substitutes and essential nature of the products.
Step-by-step explanation:
An example of a good or service that probably has a highly inelastic demand curve is life-saving drugs or gasoline. These products are considered necessities with no close substitutes, meaning that consumers need them regardless of changes in price. Life-saving drugs, in particular, are essential for health and survival, and patients will pay whatever price is necessary to obtain them. Similarly, gasoline is required for transportation and is difficult to substitute, especially in the short term, making its demand highly inelastic as well.
While perfectly inelastic demand is an extreme case, it represents a situation where the quantity demanded does not change regardless of price. This is mainly theoretical, but goods and services essential to life or without substitutes illustrate the concept of highly inelastic demand in the real world.