Answer:
The pressure decrease with the passage of time due to again dissolution of carbon-dioxide gas in the liquid solution.
Step-by-step explanation:
In soft drinks, the carbon-dioxide gas is added in the drinks with high pressure because carbon-dioxide is a gas which is insoluble in soft drink at room temperature but soluble in the drinks at high pressure so when the pressure is removed from the soft drink, the carbon-dioxide gas releases in the air with the passage of time. But in close bottle , there is no place of escape so it again dissolve in the solution.