pop down的用法和樣例：
例句
- Pop down to the shops and get a bottle of milk.
快到下面的商店裡去拿瓶牛奶來。 - If you like, I'll pop down to the station and find out.
如果你要的話，我就跑到車站去查一查。 - If air is needed, the oxygen mask in the plane will pop down by itself.
如果空氣缺乏，飛機內的氧氣面罩會自動放下。 - Pop down when you get time. It's always nice to see you.
有時間就來，看見你總那麼高興。
