Reading flashcards for practice with specific types of questions:
https://www.varsitytutors.com/act_reading-flashcards
Other helpful websites:
http://blog.prepscholar.com/how-to-get-36-on-act-reading-11-strategies-from-a-perfect-scorer
http://blog.prepscholar.com/complete-official-act-practice-tests-free-links
http://www.act.org/content/act/en/products-and-services/the-act/test-preparation/reading-practice-test-questions.html?page=0&chapter=0
http://www.testpreppractice.net/ACT/Reading-Comprehension-ACT-Practice-Tests.aspx
