sentence: A young man wearing a green shirt is talking about the techniques involved in rock climbing. sentence:  Two young men are seen climbing the wall while being suspended on ropes. sentence:  There's another young man who is demonstrating how to climb up the wall while holding onto the wall mounts. sentence:  The man in the green shirt explain the technique as he points to the wall to show the significance of each rock and its height. sentence:  He shows various rocks that are named differently and as assigned different numbers.