You can talk to their teacher and see where, er, the pronunciation is not correct. I'm sure it won't be too many, but one or two may be a person's local dialect. If the teacher is normal, he will also make some sounds of that tape. You can listen to that voice more often. For a better solution, I also went to dock with their teacher to see if I could solve his pronunciation problem and point it out directly to the teacher. It is helpful to you, and I hope to adopt it!