Machine Learning by Andrew Ng

Hi I have completed this course September 15-December 7, 2015 session. It started as a accomplishment-only and became a certificate course few weeks. So few of my assignments are “not verified”. Now I want to get it verified and earn certificate. But the grader is locked. So my question is: 1. When will be next session? 2. Will my progress be saved in that session also or I have redo afresh? 3. In the course page it is offering me to “purchase certificate”. Will the grader be unlocked once I purchase the certificate? If not then why it is offering to buy a certificate? Please help me out. I want to complete ( only 5 quizzes are not verified , to be specific) the course and get a certificate.

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