apps for cutting audio

Yes, I have accents in English speaking. So, I am adjusting my accents---imitate sentence by sentence. How can I extract (not only rip a track) a sentence from audio files (e.g. mp3)? The following apps help:

• audacity
• mp3splt
• mp3cut
• mpgedit

Or try mp3cut online:
http://mp3cut.net/