大家好，请问一下：
牛津双解第四版对vampire的解释是
vampire n.
reanimated corpse believed by some to leave its grave at night and suck the
blood of living people
如果是这样我可以理解
reanimated corpse believed to leave its grave at night and suck the blood of
living people
但它又加了by some（应该是指“被某些人”...）
如此的话，believed不是就被by some先“用掉”了吗？
变成reanimated corpse (believed by some) to leave its grave at night and suck
the blood of living people
这样意思能通吗？（也就是括号内可删去）
还是说believed既可以被by some使用，又可以再接to leave...
有这种用法吗？
谢谢！