I haven't seen Anna since she left our hometown two years ago, but we do keep in touch with each other by sending e-mails __________.
_____ that dress when he first saw you in the street?
He _____ English for ten years by the time he takes the examination.
I knew I could not finish the homework _____.
—Where is Peter? —He _____ to Shanghai.
My brother _____ the Youth League since 1990.