noob rules question - how many weapons can you shoot in the shooting phase?

I feel so dumb asking this but the rules say on pg 179, section 3 "choose ranged weapon" - If a model has several weapons, it can shoot all of them at the same target ...". To me that reads clearly that if a tactical squad space marine has a boltpistol and a boltgun, it can shoot both at an Ork. But that doesn't really fit any of the examples of combat they give later, and neither does it really make sense. To me, it would make sense that you pick which weapon you're going to fire and you then don't get to fire the others.