What's the difference between the first stroke and the last stroke of Sha Bai's poem?

At first, "an oar" refers to the need to paddle in and out of the water town, which represents the mode of shipping and transportation;

The latter "rowing well" means that children in water towns can row well, which represents the skill of rowing.

The original intention of paddles is the propulsion tool of ships, but they are all used to refer to other meaning related to ships in poetry.

The shape of an oar is a bit like an oar, but it is bigger. Usually supported on the oar eaves of the stern or ship's side. One end enters the water in a bow shape, and the other end is tied to the boat. Shake the cornice rope by hand to make the paddle board extending into the water swing left and right.