Yes, many live in the Gobi
Yup....they do
An ecosystem is a place where plants and animals ( maybe humans ) live and animals and plants live in the desert so … 
Yes, humans work in the deserts of the world and have many of the same occupations as people who do not live in a desert - doctor, lawyer, nurse, teacher, farmer, rancher, shop owner, hotel worker, etc.
garts
yes, scientists live there
Yes, there are many species of birds that live in the desert.
Cottontails Do live in the desert hence the name DESERT COTTONTAILS. They are scattered around the world in many places
Fleas do not live in the desert per se. They live on animals as parasites and many times those animals are in the desert.
not really, but if they did they would have to have a big supply of water
Actually, Alaska has a lot of tundra in the northern part of the state but this is a distinct biome and not a true desert. Antarctica is a true desert however. People do live in the Arctic Tundra, however.
Nearly all humans that live in the desert today live in, or near, towns where stores, markets and restaurants are found. Food is generally not a problem.