Teachers                    Students                     StudentTeacherRelations
********                    ********                     ***********************
TeacherId                   StudentId                    TeacherId
FirstName                   FirstName                    StudentId
etc...                      etc...

public class Student
{
    public int StudentId { get; set; }
    public string FirstName { get; set; }
    // etc
    public IEnumerable<Teacher> Teachers { get; }
}

HomeworkAssignments          Questions                      Answers
*******************          *********                      *******
HomeworkAssignmentId (pk)    QuestionId (pk)                AnswerId (pk)
...                          HomeworkAssignmentId (fk)      QuestionId (fk)
                             ...                            StudentId (fk)
                                                            ...

StudentHomeworkAssignmentRelations    TeacherHomeworkAssignmentRelations
**********************************    **********************************
StudentId (fk)                        Teacherid (fk)
HomeworkAssignmentId (fk)             HomeworkAssignmentId (fk)

var answersToTheLastExam = context.Students
                  .SelectMany(s => s.HomeworkAssignments)
                  .OrderBy(ha => ha.Date) // this might need modifying to get the last one first
                  .First(ha => ha.Questions.Count() > 0)
                  .SelectMany(ha => ha.Questions)
                  .SelectMany(q => q.Answers)
                  .Where(a => a.StudentId == myId)

var result = (from orr in _context.ObjectRoleRoles
                         inner join r in _context.Roles on orr.RolesId equals r.Id
                         inner join or in _context.ObjectRoles on orr.ObjectRolesId equals or.Id
                         where orr.RolesId equals 1
                         select r).ToList();