Assertion: smallpox's contact | /r/HasProperty | required
Facets:
value: usually
type: DEGREE
Source sentences:
text: To pass the disease on to someone else, direct face-to-face contact is required.
text: Usually, fairly prolonged face-to-face contact (three or more hours) is required.
text: Usually, fairly prolonged face-to-face contact (lasting 3 or more hours) is required.
text: Usually, fairly prolonged face-to-face contact (3 or more hours) is required.