Keep up!!!

You are interpreting a high school English lesson. The teacher is teaching and reading quickly as she feels pressure to get her lesson in before her iPad timer rings. You are frantically keeping up but feel your doing a lousy job conveying information. You check in with your students asking a broad question about the topic. They answer correctly but still give puzzled faces back to you. You ask what's up and they say the teacher is going too fast. You ask if they want to review the info again.

--is this type of interaction appropriate? You do it all the time and see others do it too
--when the student ask for vocab clarification, is it ok to give them a definition or should you call the teacher over.