Only once. However, students who miss the exam (never start the exam) can contact the teacher personally for requesting re-open of exams. As for students who already taken the exam, they cannot take the re-open exam.
Go to User Directory > Under Teacher Directory section, select 'Go' > Search your teacher's name, then your teacher's email address will be appeared
Yes, you can, just choose a new answer and click the 'Save' button again.
Yes, you can click 'Previous' and 'Next' button to navigate back and forth to read the questions without saving answer. If you want to save answer, click the 'Save' button.
Yes, you will be redirected to your result page after you click 'Finish & Exit Exam' button.