I want to know the answer to the following question:
In what year did Lodygin demonstrate a lamp at the World's Fair?
All the background I'm provided with is that "Later he lived in the USA, changed his name to Alexander de Lodyguine and applied and obtained patents for incandescent lamps having chromium, iridium, rhodium, ruthenium, osmium, molybdenum and tungsten filaments, and a bulb using a molybdenum filament was demonstrated at the world fair of 1900 in Paris.". Is that enough to answer the question?
Answer: yes