a long shot的用法和樣例：
例句
- Looking for her in the library was a long shot; I had no idea where she was.
在圖書館中想找到她是不大可能成功的嘗試，我不知道她在哪兒。 - John was a long shot for mayor.
約翰競選市長，當選希望很小。 - It's a long shot, but I should say she's about forty.
這不好猜，但我猜她大約是四十歲左右。 - It's a long shot but I think John must have stolen the bike.
這只是一種猜測，但我認為一定是約翰偷了自行車。
