Meters
The most appropriate SI unit for expressing the mass of a single brick would be kilograms (kg).
The most appropriate metric unit to measure the mass of a concrete block is kilograms (kg).
Miles would be the most appropriate unit of length for measuring the distance between Las Vegas and Los Angeles.
Liters or gallons would be appropriate units of measurement for measuring the volume of a large pot.
Venn diagram.
histogram
A metre would be the most appropriate unit.
It depends on what you're measuring it for. You could be testing it for the following measurements: Height (using meters would be the most appropriate). Length (using meters would be the most appropriate, kilometres if long enough) Mass (tonnes would be the most appropriate). Volume (m3 would be the most appropriate). Area (m2 would be the most appropriate). Time taken to cross (depends on the length of the bridge. Minutes and seconds would be appropriate).
A Venn diagram would be the most appropriate representation for the statement "If it is not a gorilla, then it is not an ape." There would be two circles, one representing gorillas and one representing apes. The area outside of the gorilla circle but still inside the ape circle would be shaded to indicate that there are other types of apes besides gorillas.
Doctor would be most appropriate
Anything would be appropriate, but would be most appreciated might be a monogrammed necklace or even a handbag.
Formal language is the most appropriate language when writing a business letter.
Filtration. :)
kilograms
15
I think the most appropriate would be "Leader".