1 - An african (black) man and woman.
2 - A european (white) man and woman.
3 - An asian (yellow) man and woman.
4 - An aboriginal north or south american (red) man and woman.
5 - An ocean scene with birds, fish and animals.
6 - A mountain scene with birds, insects and animals.
7 - A desert scene with birds, insects and animals.
8 - A tundra scene with birds, insects and animals.
9 - A grassland scene with birds, insects and animals.
10 - A boreal forest scene with birds, insects and animals.
11 - A temperate rain forest scene with birds, insects and animals.
12 - A tropical rain forest scene with birds, insects and animals.
13 - An arctic scene with birds, insects and animals.
14 - An antarctic scene with birds, insects and animals.
15 - The pyramids.
16 - The parthenon.
17 - The taj mahal.
18 - The slums of a major third world city.
19 - The biggest, ugliest industrial site I could find.
20 - The worst scene of a starving populace I could find.
Why? To serve as a warning.
It would would take a while, but heck, it's not every day you get an assignment from the Universe!
Murray