What happens next in this paragraph?

How to do a front aerial on the beam
Stretch well.
It's safer if you stretch for at least 10 to 15 minutes, before attempting difficult skills.
Practice on the floor, and along a line.
Select from the following.
a). A couple of prerequisites, (things you need to be able to do first) are a front walkover on the beam/line. Also, you'll need to be comfortable doing a front aerial, on the floor and line first.;
b). Hang a chair over a partner who can sit up. Walk in one direction-back to a wall and whip up your arms.;
c). Keep the beam steady and level and you will execute all the moves in " front aerial " mode. Your leg muscles, arms, and upper body will all be engaged in the front aerial if you stretch first.;
d). It might hurt at first but you'll get in shape later. Get your equipment, ready for the test.;
a).