Please choose the correct solution to the question: How do I know if I am successfully removing the air bubbles from concrete while pouring when making a countertop?

Solution1: When vibrating or rapping the mold, you should see air bubbles on the surface if it's working

Solution2: When vibrating or rapping the mold, you should see water bubbles on the surface if it's working

Answer format: solution1/solution2
Answer: solution1