听力原文： A certificate of deposit (CD) is a time deposit with a bank. Time deposits may not be withdrawn on demand like a check account. CDs are generally issued by commercial banks but they can be bought through brokerages. They bear a specific maturity date that usually lasts from 3 months to 5 years, a specified interest rate, and can be issued in any denomination, very similar to bonds. CDs offer a slightly higher yield than T-Bills because of the slightly higher default risk for a bank, but overall the likeliness of a large bank going broke is pretty slim. Of course, the amount of interest you earn depends on a number of factors such as the current interest rate environment, how much money you invest, the length of time, and your specific bank. 24. What is a CD? 25.Which of the followings generally issue CDs? 26.How long does a specific maturity usually last? 27.Why do CDs pay higher return to investors than T-bills? (24)