Pronunciation does not really matter as long as you are understood. Most people improve with fluency, others do not. Arny got top jobs despite his really strong accent.

Thanks, Kraut9~ I think you are absolutely right. Understanding each other is the most important thing. But my job requires that the better your pronunciation is, the more excellent you may be. Therefore I believe if I could speak better both in the fluency and accuracy ,that would be so great.

Follow the movies dialog , often practice.