REMOVE

1. machinery
2. white
3. workers
4. farms

WHAT

1. Visual Works (hierarchy n … (1)
2. banks (landforms) (1)
3. black-and-white film (1)
4. bushes (1)
5. freight cars (1)

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WHO

1. Clyfford Still; Still, Cl … (1)
2. Still, Clyfford (1)

WHEN

1. 1920 (1)
2. 1940 (1)
3. between 1920 - 1940 (1)