Thanks for the reply, Gustavo. Can I ask you another question?
This is the transcript of a short conversation and I don't understand her answer:
(Man): Dr. Brighton’s Biology quizzes are short and tricky.
(Woman): Aren’t they, though?
Maybe I do, but I cannot explain it; considering "if you understand it, you can explain it" then I don't understand it fully. What troubles me is the "though" part. I think the "aren't they" is an agreement of the statement he made and I just can connect the two parts.