Subject	plant
Predicate	has_property
Object	necessary
Modality	Modality Occurrences
Polarity	POSITIVE
Plausibility	0.9861
Neighborhood Sigma	0.9861
Local Sigma	0.9861
Example Sentences	Sentence Occurrences Source plants are necessary for life on earth 3 Google Autocomplete plants are necessary for survival 1 Answers.com Questions plants are necessary in the ecosystem 1 Answers.com Questions