Assertion: radon's level | /r/AtLocation | earth's crust
Facets:
value: widely
type: DEGREE
value: naturally
type: MANNER
Source sentences:
text: Naturally existing, low levels of uranium occur widely in Earth's crust.
text: Naturally existing, low levels of uranium occur widely in Earth's crust.
text: Naturally existing, low levels of uranium occur widely in Earth's crust.