Brain vs. Mind

The following sentences contain idioms with either 'brain(s)' or 'mind'. All you have to do is to fill in the blanks with the suitable word.

1. I hate having to start work at 7. I'm sure it was Samuel's _________-child, as he simply can't sleep after 5.
2. I don't think you should beat about the bush much longer. You are an outspoken person; you always speak your __________, so just be you and you'll succeed.
3. I enjoy exotic places but it never crossed my ___________ to go camping in Kuala Lumpur.
4. As I was walking home yesterday I suddenly had a __________ wave and now I know what I'm going to do with my life.
5. I have been racking my ___________ for more than two hours but I simply can't remember her phone number.
6. Their child has gone on a biking tour without telling them. I'm sure they will give her a piece of their ___________ when she comes back.
7. I don't have the least idea how to finish this essay; I would like to pick your __________ for a good ending, if you don't mind.
8. I understand that it is very hard to choose between these two boys but you've been sitting on the fence too long, it is just about time you made up your____________.
9. He is a very independent young man. He has a ___________ of his own and I think he has a brilliant future in the business world.
10. Why don't you come with us to see the new Stallone movie? It is so funny it will certainly take your ____________ off your problems.