If you don't understand something, you may research, study, and talk to other people _______ you figure it out.
because
though
until
since
—Do you need the electric dryer? —________.
—Why are you moving out? —________, but I just don't like the atmosphere here.
—Believe it or not, I have met him before. —No kidding? ________ you've never mentioned it?
—What's the capital of Bhutan? —________ Let's go online and find it out.
—I hear Kris had an accident as he was riding his bike to school yesterday. —________? He is always so careful when he is riding.