Question

select the misplaced or dangling modifier.
gazing at notre dame cathedral, the gray-green water of the river seine rushed by, carrying heart-shaped leaves recently fallen from linden trees.

Explanation:

A dangling modifier is a phrase that lacks a clear subject it modifies. Here, "Gazing at Notre Dame Cathedral" is a participial phrase that logically should describe a person (the one doing the gazing), but the sentence's subject is "the gray-green water of the river Seine," which cannot perform the action of gazing. This makes the phrase a dangling modifier.

Answer:

Gazing at Notre Dame Cathedral