填空题 There are two reasons why demand is related to price. For one thing, if your income stays the same, you can afford to buy more when the price is low. Secondly, records, for instance, are more attractive when their price is lower than the price of similar products. If records are less expensive than cassettes, you may choose to spend your money on records.
In reality, the demand for a product is not always the same. It changes under different conditions. For example, taste may change. You may decide that you prefer cassettes because records are inconvenient. Consequently, you will buy fewer records at both high and low prices. Demand may also change as a result of changes in the prices of other products. For instance, the price of records stays the same, but the price of cassettes falls. Therefore, you buy more cassettes and fewer records. Or, income may change. Due to an increase in income, you can afford more records whether the price is high or low.
The demand for a product has a close relation with 1 .
One may choose 2 rather than cassettes because 3 .
4 may change under different circumstances, which affects demand.
Regardless of price, 5 is a good way to increase demand.