Keisha is creating an input mask and needs to ensure that the user will only enter digits into the field. Which two characters do NOT enforce this rule?

0 and 9
9 and ?
? and L
L and 0

After the price floor is instituted, the chairman of productions office buys up any barrels of gosum berries that the producers are not able to sell. with the price floor, the producers sell 300 barrels per month to consumers, but the producers, at this high price floor, produce 700 barrels per month. how much producer surplus is created with the price floor? show your calculations.