Student or Learner
The original sentence is: It was claimed that the drug produced no undesirable side - effects.
I'm trying to do a passive voice sentence and I wonder if it should be 'The drug was claimed to be producing no undesirable side - effects' or 'The drug was claimed to produce no undesirable side - effects'
In the textbook I use there are examples only with the verb 'be' and I'm not sure what to do with other verbs...
The first clause is already passive.
"It was claimed that no undesirable side-effects were produced by the drug."