Sentence:  It is made up of tumbling , which might be said to start with a somersault , run through such <WSD>stunts</WSD> as headstands , handstands , cartwheels , backbends , and culminate in nearly impossible combinations of aerial flips and twists and apparatus work . 
Meaning of the word marked with <WSD> tags:  a difficult or unusual or dangerous feat; usually done to gain attention