REMOVE

1. groves (plant communities)
2. sky
3. black-and-white film
4. automobiles

WHAT

1. Visual Works (hierarchy n … (1)
2. artists (visual artists) (1)
3. branches (plant component … (1)

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WHEN

1. 1960 (1)
2. 1970 (1)
3. between 1960 - 1970 (1)