The Zibda on this grammar is that we need to be careful when using items in a series. We need to keep our grammatical structures the same.
This is NOT Parallel: The students listened to the teacher, read the text were interacting with each other.
This is Parallel: The students listened to the teacher, read the text and interacted with each other. (Notice that all the verbs are the same verb tense)
This is NOT Parallel: The teachers dealt with the problem swiftly and without making noise.
This is Parallel: The teachers dealt with the problem swiftly and quietly. (Notice that the both words are adverbs)
I recommend watching the following video for further explanation.