1. The subject of organ transplants on the mainland makes disturbing reading, with organ harvesting from executed prisoners.
Does 'reading' mean 'study' or 'come to know'?
Yes, in a sense. X makes disturbing reading means that upon reading about X, we are disturbed by what we learn.
2. It is a tall order to expect the surgeons to make a difference on their own.
What is the meaning of 'tall' here? The idiom 'a tall order' means any formidable task or request. 'Tall' is used in the sense of 'difficult'.
'Finishing the project in a week was a tall order, but we worked night and day to get it done.'
I hope this is helpful,
Student or Learner