Ⅱ. Choose the proper words to complete the sentences.（选择恰当的单词完成句子。）
1. She decided to (play, volunteer) at the science museum, where she could learn more about new inventions.
2. The inventor found a (serious, complete) mistake in the design and had to start over.
3. To everyone's (worry, surprise), the simple wooden machine actually worked very well.
4. Many stores will have a big (sell, sale) during the holiday season.
5. The phone is light, fast, and has a great camera. (Even if, In short), it's the perfect choice.
6. The new smartphone (took, cost) me about 5000 yuan.
7. It's a good habit to save money regularly, (as if, even if) it's just a small amount each week.
8. Please (exchange, complete) the form with your personal information to open a bank account.
9. Food and drinks (account for, pay for) most of my weekly spending.
10. Be careful with the project details, or you might (deal with, mess up) everything.

1. volunteer
2. serious
3. surprise
4. sale
5. In short
6. cost
7. even if
8. complete
9. account for
10. mess up