1) drop someone a line; send someone a letter
写封短信给..;留便条给..
2) drop sB. a line
给某人写封短信
3) Drop me a note.
给我留了张便条
4) I'll drop you a line.
我会留个便条给你
5) pen a note to one's friend
给朋友写一张便条
6) Drop me a line!
给我写信！
参考词条