It's the most simple-- or often called a bill-- a discount bond does not pay interest; it's sold at a discount.

它是最简单的,经常被称为国库券,它是一种贴现债券,且不付息,并以折扣价发行

耶鲁公开课 - 金融市场课程节选

This is insurance that you pay each year for insurance in that year and it does not build a cash value.

为了这种保险可以持续生效,你每年都要缴纳保费,保费不产生现金价值

耶鲁公开课 - 金融市场课程节选