a flash in the pan
曇花一現 ；虎頭蛇尾; 短暫的成功
a sudden success that lasts only a short time and is not likely to be repeated；something that happened only once or for a short time and was not repeated；a person or thing that starts out well but does not continue
flash指「閃光」，pan指「舊式槍的火藥池」。a flash in the pan指「火藥在藥池點燃後所發出的閃光」，一般用來形容某事「看起來華麗而持續時間極短暫」。比如：
He used to be called a young entrepreneur. But soon he was forgotten by the public. He was a flash in the pan.
他曾被譽為青年企業家。但不久就被公眾所遺忘。他真是曇花一現啊。
Don』t count him in. You know him. His determination is always a flash in the pan.
別把他算進去。你還不了解他嗎。他的決心持續不了三分鐘。
Some industry watchers predict these sites will change the way we shop, but others wonder whether online flash sales are a flash in the pan.
有業內分析家預測這些網站將會改變人們的購物方式，但也有些人懷疑網上閃購只是曇花一現。
Sadly, their success was just a flash in the pan.不幸的是，他們的成功僅僅是曇花一現。
Mary got 100 on the first test in arithmetic but it was just a flash in the pan because she later failed several times in arithmetic．瑪麗第一次算術考試得了100分，但只是曇花一現，因為後來幾次算術考試都不及格。
That singer can't last. he's a flash in the pan.
那歌手不能持久，他只是曇花一現。
He was indeed popular for a short time, but he didn't last long, just a flash in the pan.
他的確紅了一陣子，但好景不長，只不過是曇花一現而已。
Her success as an actress in the show business was only a flash in the pan.
作為演員，在演藝界的成功只是曇花一現。她的餘生默默無聞。
They won the first match，but it was only a flash in the pan，they lost all the other games．他們贏了第1場比賽，可是好景不長，後面幾場比賽全輸了。
He was indeed popular for a short time， but he didn't last long， just a flash in the pan．他的確紅了一陣子，但好景不長，只不過是曇花一現而已。
People will be looking in to see how good we are now and whether our success has just been a flash in the pan.
人們會來看看我們現在有多成功，看看我們的成功是否只是曇花一現。
《柯林斯高階英漢雙解學習詞典》
I'm afraid that my success as a painter was just a flash in the pan.
我擔心我當畫家的成功只是曇花一現。
I wish I could be with you forever, even though it happens as a flash in the pan, Iwould not have any desires.
但願我能永遠伴隨在你身邊，就算僅僅只是是曇花一現，我亦別無它求！