When they arrived, they found the ship had been sunk.
请问这个句子对吗？其中的 been 是不是多余的？如果有 been，这个 sunk 就应该是形容词表示“沉没”，这也对吗？
你的句子去掉 been 也可以，但意思稍有不同：
When they arrived, they found the ship had been sunk.——强调使船沉没的外力，即暗示它是被弄沉（比如被击沉等）
When they arrived, they found the ship had sunk.——不强调使船沉没的外力。
