Dưới đây là các câu hoàn chỉnh từ những gợi ý đã cho:

1. Frank exchanged some used paper for notebooks yesterday.
2. Mr. Ryan did not run a marathon to raise money for a charity last Sunday.
3. Donors gave 50 homeless people a sum of 7,500 US dollars last year.
4. She started volunteering at the Clearlake animal shelter five years ago.
5. We donated old textbooks to children in rural areas.