HE Student Knowledge Base URL: http://cmg.screenstepslive.com/s/MacmillanMedia_StudentHelp/m/52448/l/609360
You can submit assignments as long as the due date has not passed. You must answer all the multiple choice questions in order to submit them. You will get a notification that your submission was successful once you click Submit.
You can go back to your course page to double check. If it says Submitted or View Grade next to the Short Answer or Multiple Choice links, then you can be sure it was successfully submitted.
If you are still having difficulty submitting, please clear your entire browsing and download history, cookies, and all cached images and files.