Completed Sentences:
- Dave Cornthwaite from Wales, became the first person to skateboard across Australia. He set a new world record, by skating a total of 5,823 kilometres.
- He went through great physical pain and he got extremely sore feet.
- If Dave hadn't believed in making his dreams come true, none of this would have happened.
- He wanted this journey to be about something more than just him so he created BoardFree, an association that would raise money for charities.
- This journey had challenges. (Assuming 'challenges' would be a word in the original word list which is not provided here in its entirety. Based on context, it fits best.)
- He travelled across the Australian desert where temperatures reached 48°C in the day and 0° at night. He had a serious accident in Adelaide where he jumped on a piece of metal that cut through his heel. He also had a nasty fall down a hill where he banged his head hard on the pavement and twisted his ankle.
- Dave helped raise money for children's charities, wrote a book and motivated others to follow in his footsteps. (Assuming 'raise money' is a phrase from the word list.)
Note: Some words from the original list might not perfectly fit the gaps without the complete context or exact word choices provided in the exercise. I have made the best fit based on the surrounding text and common collocations. Sentence 5 and 7 required assumptions based on the context and typical exercise structures.