Final answer:
When the front tire goes flat while riding a bike, the correct action to take is to gradually reduce speed.
Step-by-step explanation:
If the front tire goes flat while riding a bike, the correct action to take is to gradually reduce speed. This is because sudden braking can cause loss of control and increase the risk of accidents. Accelerating or changing gears immediately may also lead to loss of balance and make it harder to control the bike.