2. The bike was expensive; therefore, no one bought it. → No one

3. "Don't make such a mess in your room," said Mrs. Quyen to her son.

→ Mrs. Quyen told

4. If he doesn't apologize, I will never invite him here again.

Unless

5. He said: "I can't find my umbrella.' → He said

6. We couldn't find a taxi, so we walked home.

→ Due to

8. "Do you see Peter around here?" she asked her friend Jack

→ She asked her friend Jack

9. Even though it was very cold, she wasn't wearing a coat.

→ In spite

10.It was such a boring film that we left before the end.

→ The film