Which one is correct?
_____ they read books at night.
A. Always B. Usually C. Often D. Sometimes

Question

Which one is correct?
_____ they read books at night.
A. Always     B. Usually     C. Often     D. Sometimes

Answer

Emma is right. For future reference always almost never comes at the start of a sentence. 
I have to say that none of those sentences sound very 'natural' though. 'They usually read books at night' flows better.

Answer

This question is wrong! The only one which is incorrect is 'Always they read books at night.' All the others are correct.

Answer

Usually they read books at night.

Answer

And why?