Sentence:  He said he had spoken to a woman who was kayaking off Catalina Island, California, in 2008 when a <WSD>shark</WSD> slammed her kayak from underneath and sent her flying into the air. She then landed on the back of the <WSD>shark</WSD>, Collier said. "At that point the <WSD>shark</WSD> started to swim out to sea, so she jumped off its back," Collier said. 
Meaning of the word marked with <WSD> tags:  A scaleless, predatory fish of the superorder Selachimorpha, with a cartilaginous skeleton and 5 to 7 gill slits on each side of its head.