麻烦你了
在向别人请教时可以说 excuse me ,或者 sorry to bother you
请教完后可以说 thanks 或 thanks for your time.
恰巧
What a coincidence! 或者是 it happend(s)(ed) that...
对不起,麻烦你了:sorry to have troubled you so much.
恰巧:by chance、as luck would have it、happen
麻烦你了: Sorry for imposing (you)
恰巧: coincidence
Excuse me
by chance