If you are a student and you are taking a quiz and cannot submit the quiz, are not sure you submitted the quiz or while taking or submitting the quiz your Internet connection timed out then first you should contact your instructor. Only your instructor can allow you to access your quiz more than once.
To prevent your Internet connection from timing out or from losing any questions you have completed be sure and click the save icon above and to the right of each question. Then if you do get disconnected your instructor will be able to view the questions you've completed. If you do not save your questions your instructor will be able to see you have accessed the quiz but will have no evidence that you attempted any questions.
It is recommended that you use a broadband connection but if you do not have broadband available check with your dial-up Internet service provider (ISP) to see what their time-out policy is. Many dial-up connections automatically time-out after a period of inactivity.
As an instructor you can put a relatively small number of questions per page when creating the quiz. This will force the student to save after every page and will ensure the student is refreshing the Internet connection by saving and going to another page.