Symmetric cleavage of β-carotene yields _____ molecules of all- trans -retinal, which can be either further oxidized to all- trans -retinoic acid, or reduced to all- trans -retinol, vitamin A 1 .
【单选题】Suppose there is a 10 percent increase in the price of good X and it causes a 10 percent decrease in the quantity of X demanded. Price elasticity of demand for X is
【单选题】Suppose there is a 6 percent increase in the price of good X and a resulting 6 percent decrease in the quantity of X demanded. Price elasticity of demand for X is
【单选题】Suppose there is a 6 percent increase in the price of good X and a resulting 6 percent decrease in the quantity of X demanded. Price elasticity of demanded for X is