Which word signals a nonrestrictive clause in a complex sentence?

the choice that is not a technique that you should use to come up with ideas for the topic of a research project is, writing about academic subjects that are not interesting to you. this does not belong to the techniques to come up with ideas because having no interest in a certain topic will lose your drive to come up with better ideas. it gives no room for improvement and acquiring of new ideas and information. 

explanation:

caliban is prospero's slave in the shakespear's play "the tempest"

i needs a girlfriends