ReadWorks has a wealth of reading passages on a variety of topics, with accompanying questions. And it's free! You do have to sign up for an account to fully access the site.

While designed for K-12, many of the passages and articles can be used for adult learners.

Articles and questions may be printed or assigned online to the class that you create in your account. Online versions of articles also come with an audio option.

Many teachers have found this site to be a gem of a resource.