Yes, the one about the オノマトペ was great. Still confused by the fact it’s onomatopeia in English, like either langague just removed or added a sillable at the end? 
Edit: I had assumed it was a Japanese word, but it’s actually Greek-origin. That explains that, just 外来語-Katakana-conversion I guess.
It is a lot of content. Well, the book certainly makes us read, listen, just consume, which is always good, should have done a lot more of that on my way to 60!~ 
Your Level 21 before 2021! - #987 by Marifly is honestly a really good approach, something I agree much more with now than when I set out to reach 60 at max-speed from level 30, fall last year or so.