Dilemma #4

Alrighty, so this week's dilemma consists of my students and their grades. I am extremely frustrated with how my students are performing. I gave a quiz to my students about Adjectives and Adverbs; this type of material is meant to be a review for them. When I began to grade the quizzes for my first two periods, the highest grade I was seeing was an eighty-three. The students were consistently getting sixty-ones. So I immediately starting questioning if the quiz was too difficult, but once I started grading third period's quizzes, my doubts were gone. The highest grade received changed to an eighty-nine and then I had a student (unexpected student that doesn't perform that well) receive a ninety-four. So I knew automatically that the students are capable of receiving As on this quiz. The students are just extremely lazy. I talk to all of my teachers that are on the team and they agree. They have never seen this amount of lazy students on one team. After looking into certain students' grades from my mentor teacher's class and the other team teachers classes, we have found around 3/5 of the students on the team are predicted to attend summer school. I've tried doing activities with the students, I've tried watching Brainpop videos, I've tried making changes to the ways I teach or talk about the material... nothing changes. What do I do?