Multiple form Validations

I have the following JavaScript that I am trying to use. Can someone assist and tell me what is incorrect? I would greatly appreciate any help

<script type="text/javascript" src="/SiteAssets/jquery-1.12.4.min.js"></script><script type="text/javascript" src="/SiteAssets/jquery-3.4.1.js"></script><script type="text/javascript">
        function PreSaveAction() {
drop1 = $("select[title='Supervisor Completed']").val();
date1 = $("input[title='Supervisor Date Completed']").val();
drop2 = $("select[title='IMO Completed']").val();
date2 = $("input[title='IMO Date Completed']").val();
drop3 = $("select[title='IAM Completed']").val();
date3 = $("input[title='IAM Date Completed']").val();
    if (drop1 !=="Select One..." && date1===""){
        alert("The Supervisor Date Completed is a required element. Please Fill this date out.");
        return false;
    }    
        return true;
}
    if (drop2 !=="Select One..." && date2===""){
        alert("The IMO Date Completed is a required element. Please Fill this date out.");
        return false;
    }    
        return true;
}
    if (drop3 !=="Select One..." && date3===""){
        alert("The IAM Date Completed is a required element. Please Fill this date out.");
        return false;
    }    
        return true;
}
        }</script>

Lee Mossolle