Birds which eat whole seeds needed the gravel to grind the food in the crop.
(Birds which eat whole seeds; needed; the gravel; to grind the food in the crop) Context(Birds which eat whole seeds needed,List([0, 34))):(Birds; eat; whole seeds) Context(Birds which eat whole seeds needed,List([0, 34))):(Birds which eat whole seeds; needed the gravel to grind; the food)
Birds which eat whole seeds needed,List([0, 34)) Birds which eat whole seeds needed,List([0, 34))
Birds which eat whole seeds Birds Birds which eat whole seeds
needed eat needed the gravel to grind
the gravel to grind the food in the crop
whole seeds
the food