We ________ each other since I came to Beijing, but we send emails very often.
A.don't see B.didn't see C.won't see D.haven't seen
D
【详解】
句意:自从我来北京,我们就没见过面,但我们经常发电子邮件。
本题考查时态。don't see是一般现在时;didn’t see是一般过去时;won’t see是一般将来时;haven’t seen是现在完成时。根据since I came to Being可知,此处用现在完成时,故选D。