Vertical composition is also to write a general argument first, and then write this argument: what, why and how to do it. For example, to write that happiness is extremely precious, you can write the following arguments: what is happiness (you can say your own opinion or quote famous sayings), why happiness is extremely precious, and what should we do.
For reference only, our teacher said so. I hope it helps. In fact, it is to write an argument around the theme, then find out the argument to prove it, and finally add some ideas of your own. The difference between a high score and a low score lies in whether your language is brilliant or not. The teacher said that we should pay attention to the accumulation of arguments.