Having issues in school

Despite my son's lack of focus and constint distractions he gets high scores on testes and worksheets. So I was shocked several weeks ago when he brought home a 71% on a vocabulary test. I expressed my disappointment, went over the test, and thought he was confident for the next one.

Last week he came home with a 55% on his test! There was a note at the top of the test saying that he had three times as much time as he needed, didn't complete. So I know he is just really frustrated. I sent a note to his teacher asking for practice sheets for the questions (obviously he is getting lost in the difficult wording). Nothing! She hasn't even responded!

At this point I feel she is just out to say he isn't doing the work instead of solving the problem! I will work with him...just show me what to practice! I always have problems wording these things right. I do not want to offend her but I do want he rto know that this is MY son, not th eother 20 students she teaches!