Choose the adjective that best completes each sentence.

1. Sailing offers peaceful moments when the sea is calm. 2. One of the most popular competitive sport in the world is football. 3. It must be a thrilling experience to go skydiving. 4. He enjoys doing dangerous sports like rock climbing. 5. A good game of squash is always challenging. 6. Hiking could be tiring if a person is not fit enough. 7. Surfing the waves is very exciting. 8. Playing hockey for an hour is exhausting.