1. The only difference between the two perpetuities is that the first one also provides a cash flow in each of the years 1 t. 这两者之间的唯一区别是前者也提供了一个从1年到t年每一年的现金流。
2. There have also been one hundred-year bonds and there have also been perpetuities that--in the UK, for example, the British Consoles--have no expiration date and they have infinite maturity. 也有长达百年的债券,甚至有永久债券--比如在英国,不列颠控股,没有过期时间,永不到期。