REMOVE

1. graphite pencils
2. teaching
3. hills (landforms)
4. lines (geometric concept)

WHAT

1. Visual Works (hierarchy n … (1)
2. buildings (structures) (1)
3. drawing (image-making) (1)

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WHO

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

WHEN

1. 1933 (1)
2. 1933-1941 (1)
3. 1941 (1)