Is it possible to finish English composition II in one month on study.com?

[dfrecore]

If you can write papers quickly: yes. Unlike Sophia, the SDC papers don't rely on one another for grades. So you can submit everything as soon as you finish it. You don't even need an active subscription to get your grades back. For instance, you submit your final paper on the last day of your subscription month. You do NOT have to renew your subscription in order to receive a grade and send the SDC transcript to your school.

Assuming that you have finished all of the quizzes before your subscription period runs out.  So you should concentrate on getting those completed first, and then you can submit your papers any time after that.