I am not a teacher.
1, What is the difference between "communication" and "communications"? Where should I use "communications"?
The first is singular, and I would think it refers to a communication between two persons, whilst the plural, communications, could refer to multiple communications within a network.
2, "For the past years, doctors have tried to treat this disease with anticancer drugs, equivalent to using a hammer, to beat down the body's defences."
Is this a correct sentence? Can "equivalent" be used this way?..YES.
I hope this helps, as I am not a teacher, and what I have written are merely my thoughts. I too am learning every day on this site.
Student or Learner