Briefly compare the 3 strategies (ways) by which vertebrates…

Briefly compare the 3 strategies (ways) by which vertebrates dispose of nitrogenous waste. Please answer the following for each: 1) Name of the strategy 2) Molecule being excreted 3) Weight of the molecule relative to the others (least, intermediate, most) 4) Energy expenditure to produce the molecule relative to the others (least, intermediate, most) 5) Degree of toxicity of the molecule being produced relative to the others (least, intermediate, most) 6) Water conservation relative to the others if the animal was terrestrial (least, intermediate, most)

If a company produces product A then it must also produce ei…

If a company produces product A then it must also produce either product B or product C. Let A, B, and C reflect binary decision variables describing whether or not the company produces that product.  Which of the following constraints enforces this condition?