1. Is it advantageous that fundamental standards, such as those for length and time, be accessible, invariable, indestructible, and reproducible. Disscuss why these are advantages and whether any of thse criteria can be incompatible with others. I don't understand what it's asking. I think it is advantageous because we won't have to worry about constantly changing our system to adapt to the new one. So, people all over the world can convert from one number to another through the metric system. 2. Why is 516m (1693ft) incorrect? How would you change it? Is it because those aren't found in the SI units? I'm not sure how to change it. 3. What's the percent uncertainty for a measurement of 9.73? I do not know how to do this.