1. That's OK!

沒關係！

2. That's alright!

沒關係！

3. Don't worry about it!

不用擔心！

4. It's nothing!

沒什麼！

5. Never mind!

別放在心上！

6. It doesn't matter!

無所謂！

7. It doesn't make any difference!

沒差！

8. No problem!

沒問題！

9. Fine with me. / Fine by me.

我沒問題。

10. Cool!

酷！（沒事兒！）