Please choose the correct solution to the question: To blow up a balloon,

Solution1: using your mouth, press your lips over the small tube end, holding it gently up to your lips with your thumb and forefinger, then blow air outwards through your mouth, closing the tube with your fingers when you pause to breathe in more air.

Solution2: using your mouth, press your lips over the small tube end, holding it gently up to your lips with your thumb and forefinger, then blow air outwards through your mouth, opening the tube with your fingers when you pause to breathe in more air.

Answer format: solution1/solution2
Answer: solution1