If you are having difficulties progressing then please Make you sure you have followed the Course Instructions closely.
To resume your Course from the last section which you have taken :
Click on the My Account Tab on the top left of the page , then select 'My Results' and Click on the last Question which you took.
If you are still having difficulties then use the Help tab to send us a message about this - explaining where (what section/questions?) you encountered the problem.