Question

The dog fell along the river. spot the error​

Answer 1

Answer:

The dog fell into the river.

Explanation:

Here, we know that along is a preposition used to show accompanance and that does not suit here.

Answer 2

Answer:

The dog fell in the river.

Explanation:

"Along" means that the dog fell side by side the river

A better alternative would be in

Along can be used in a sentence like:

I went along with the trend

                 or

I would prefer a hamburger along with/ alongside some juice