Assertion: sweet potato | /r/HasProperty | useful
Facets:
value: in saving time
type: PURPOSE
Source sentences:
text: Potato dishes will freeze well so the sweet potato is useful in saving time and energy.
text: But sweet potatoes were so useful and so good that by about 3000 BC people had learned to grow them on purpose, and soon they shared that knowledge with their neighbors, and so after a while people were growing sweet potatoes all over South and North America, wherever it was warm enough for the plant to grow.