fibrous flutter

例句：

1. 1. The patient's condition was so severe that she needed to be kept in a fiberous flutter state.
   病人的状况非常严重，需要被保持在一种纤维状的颤动状态。
2. 2. The butterfly's wings are so delicate that they can only flutter in the wind.
   蝴蝶的翅膀非常脆弱，只能在风中轻轻颤动。
3. 3. The tree's bark is so fibrous that it can only flutter when it is cut.
   树皮非常坚韧，只有在被砍断时才会颤动。