Hi!
While I don't have as much experience in terms of non-native speakers working on reading comprehension, I would agree with mikeCoolBoy on this one. What we suggest for our students who want more practice than what they can get in the
OG guides is to read scientific magazines. In the forum thread here:
https://www.manhattangmat.com/forums/how ... t9175.html , Stacey Koprince, one of our instructors lists several good places to find articles that are similar in tone to the ones you'll find on the GMAT. These include:
https://magazine.uchicago.edu/ - particularly articles in the "Investigations" tab
https://harvardmagazine.com/https://sciam.com/ (This can get a bit too casual for the GMAT, but it's probably worth including because so many people get freaked out by science passages on the GMAT.)
To this list, I have also heard our instructors add the Economist, though a subscription to that can be pricey.
While I think that for a non-native speaker, building vocabulary is important, I would also urge you not to focus on that too much. A lot of RC passages intentionally put in big words that you don't really need to know in order to answer the questions they ask. It is more important to be able to grasp the meaning, and to know how to dissect each passage so you can refer back to the correct part of the passage quickly when answering questions.
If you haven't already, you might also think about getting a book. I know another test prep company posted some options, and I'd like to add that we also carry a Reading Comprehension book (you can read the description here:
https://www.manhattangmat.com/storeitems ... 25&catid=6 )
I hope you find this information helpful!
Best Wishes,
Caitlin Clay
Student Services Associate
Manhattan GMAT