(1) Fill the bottle with water and observe the trademark with production date through the bottle. The bottle and water form a convex lens, which acts as a magnifying glass and enlarges the production date;

(2) Fill the bottle with water and insert the bottle mouth upside down in the water, so that the water in the bottle will not flow out, which proves the existence of atmospheric pressure.

So, the answer is: the experiment introduces your operation most succinctly. The problem you want to explain in your experiment is 1. The bottle is filled with water, and the date of production of the trademark with the date of production is enlarged through the bottle, which proves that the bottle and water form a convex lens and play the role of a magnifying glass. 2. Fill the bottle with water and insert the bottle mouth down into the water. The water in the bottle will not flow out, which proves the existence of atmospheric pressure.