While the seed companies have convinced farmers of the benefits of some GM crops, they have done a poor job of explaining the benefits and risks of GM crops to the public.
(the seed companies; have convinced; farmers of the benefits of some GM crops) (they; have done; a poor job of explaining the benefits and risks of GM crops to the public)
the seed companies they
have convinced have done
farmers of the benefits of some GM crops
a poor job of explaining the benefits and risks of GM crops to the public