Collect an essay at the start of every class about reading assigned last time.
Hand out corrected essays. (Outsource this)
Discuss selected corrected essays. Distribute copies to the class.
For students whose English is too weak to follow the class' nominal subject matter:
Allow them to write about any topic in English.
Supply them with engaging reading materials based on personal interests and reading level.
Do the same collective essay correction style.
This is like good business meeting practice:
Always have an agenda before a meeting.
At the end of the class, if there is extra time, it indicates lack of interest in the material. Then show engaging multimedia to increase the entertainment value and therefore interest. Or else they are too overwhelmed with work to write more. In which case, they need to relax.
Supply textbooks both official and nonstandard, the latter selected for truth and entertainment.
Since they do not have Internet, try to supply them with info relevant to their studies and interests. (Outsource this.) Print it out and give it to them. Keep doing so if a student's essays indicate he has read it.