The yield to maturity for a perpetuity is a useful approximation for the yield to maturity on long-term coupon bonds. It is called the ________ when approximating the yield for a coupon bond.
【简答题】阅读理解。 Mr Brown was born in a poor family. He couldn't go to school when he was young. Now he's a porter and works at a station. He doesn't think it necessary to know some knowledge of science. His ...