https://online2.tingclass.net/lesson/shi0529/0009/9884/80.mp3
https://image.tingclass.net/statics/js/2012
drop in 順便拜訪;順便進入
drop in on somebody 順便拜訪某人
drop in at someplace 順便拜訪某地
例句：
The Wilsons dropped in on us just as we finished dinner.
威爾森一家在我們剛吃完晚飯時就突然拜訪。
Please drop in on us when you happen to be free.
如果你碰巧有空，請到我的辦公室來。
末尾音樂：
I Go In
