Quote Originally Posted by chaika
quartz made a couple of corrections. I would say that we can't for sure know whether the sentence should run
who think that __teachers are
or
who think that the teachers are

Correct usage would depend on the context.
You are right, of course. Given just this text, the article should be omitted. However, in a larger text, it would depend on context.
Thank you for pointing that out, chaika.