REMOVE

1. trucks
2. sky
3. plants
4. roads
5. bushes
6. hills

WHAT

1. Visual works (hierarchy n … (2)
2. blue (2)
3. figures (2)
4. machinery (2)
5. oil paint (2)

More 

WHERE

1. Pullman, Washington (1)
2. San Francisco, California (1)

WHO

1. Still, Clyfford (2)

WHEN

1. 1936 (1)
2. 1942 (1)