Every person stood to applaud his unforgettable act of courage.
所有人起立为他不可磨灭的.英勇之举鼓掌。
My first love was unforgettable.
我的初恋难以忘怀。
A visit to Rome will be unforgettable.
到罗马一游将会令人永远难忘。
He created many unforgettable characters in his novels.
他在他的小说中创造了很多令人难忘的人物。
He spent so many unforgettable days with them that he was loath to part with them.
他与他们一起度过那么多难忘的日子，他舍不得离开他们。