### Bài 14: Chuyển các câu sau từ thì quá khứ đơn sang thì hiện tại hoàn thành sao cho nghĩa của câu không thay đổi.

1. The last time I played the violin was 2 years ago.
- I haven't played the violin for 2 years.

2. The last time the team won the prize was a long time ago.
- The team hasn't won the prize for a long time.

3. She last did charity work 2 years ago.
- She hasn't done charity work for 2 years.

4. The last time I wrote a letter was 5 years ago.
- I haven't written a letter for 5 years.

5. My father stopped smoking in 2014.
- My father hasn't smoked since 2014.

6. I last donated my blood 7 months ago.
- I haven't donated my blood for 7 months.

7. When did you start doing charitable work?
- How long have you been doing charitable work?

8. The last time she involved in community service was 2 months ago.
- She hasn't been involved in community service for 2 months.

9. She said: "I began working as an activist when I was 20 years old."
- She said she has worked as an activist since she was 20 years old.

10. My best friend gave up eating fast food last year.
- My best friend hasn't eaten fast food since last year.

### Bài 15: Chuyển các câu sau từ thì hiện tại hoàn thành sang thì quá khứ đơn sao cho nghĩa của câu không thay đổi.

1. We have learned English for 10 years.
- We started learning English 10 years ago.

2. It has been a long time since we last met.
- We last met a long time ago.