Example key:
1 Firstly, you must have a professional skateboard.
2 Secondly, make sure to secure your helmet tightly.
3 Don’t forget to wear knee pads.
4 ought to check if you understand the safety procedures.
5 always bring a first-aid kit in case you fall.
6 You ought to wait when there’s still someone on the court.
7 Always check if the court is free.
8 In the end, it’s important to make sure you have fun.