每日钉一下（什么是通货膨胀？如何衡量呢？）

Group 1 - The article highlights that most investors are familiar with stock index funds but have limited knowledge about bond index funds and their investment strategies [1]. - A free course is offered to educate investors on how to invest in bond index funds [1][2]. Group 2 - The course includes additional resources such as course notes and mind maps to facilitate efficient learning [2]. - There is a call to action for readers to add a course assistant and reply with "bonds" to access the course [2].