My grandmother's goulash recipe is a family secret.

我祖母的匈牙利炖牛肉食谱是家族的秘密。

The recipe has been a family secret for generations.

这个食谱是我们家族的秘密，已经传了好几世代。

It was the sound of a family secret.

这是隐藏家庭秘密的声音。

His meadow cannot be seen from the road and has remained a family secret until a hot air balloonist took this photograph from the air.

他的丛林在路边并不能被发现，直到有人在热气球上拍照，这个秘密才公布于众。