improvement bond

例句：

1. 1. The government has issued a new improvement bond to fund infrastructure projects.
   政府已发行新的改进债券以资助基础设施项目。
2. 2. The company is considering an enhancement bond to raise additional funds for its expansion plans.
   该公司正在考虑发行一个增强债券以筹集额外资金用于其扩张计划。
3. 3. The investment bank issued a bond with a maturity date of three years, which is consideredan enhancement bond.
   这家投资银行发行的债券有一个三年的到期日，被认为是一种增强债券。