It's a system a letters that can be understood using touch. It is made for those with weak vision. This system can help blind people with understanding things from an elevator floor to a story book!
The central idea is what the main thing. For this, I think the central idea is simply Cactuses.
I'm not sure what another supporting detail can be, but if there's a back side, or another page about cactuses, I can sure help! But if that's the only side, ask your parents. xD
In English, this means: "<span>What is the relationship between speed sprints to <span>the long jump"</span></span>
