custom作為風俗是可數(shù)嗎

　　This particular custom has its origins in Wales.

　　這一特殊風俗起源于威爾士。

　　It was his custom to approach every problem cautiously.

　　謹慎地處理每個問題是他的習慣。

　　The custom of lighting the Olympic flame goes back centuries.

　　點燃奧運圣火的風俗可追溯到幾個世紀前。