CNN news articles; after reading, click on the activities on the left side: literacynet.org/cnnsf/index_cnnsf.html
These are short passages with instant feedback: http://readtheory.org/pages/advanced.html
Practice passages with comprehension questions: http://www.englishmaven.org/Pages/Reading%20Comprehension.htm
This site has links to many other practice sites; scroll down to the Reading section and choose a specific skill: http://www.internet4classrooms.com/skills-6th-langbuilders.htm