Assertion: hailstone's layer | /r/MadeOf | air bubbles
Facets:
value: often
type: TEMPORAL
Source sentences:
text: The layers of ice, which accumulate as a hailstone grows, often contain air bubbles which make the hailstone softer, lighter and less likely to cause damage.
text: The spheroidal stones often exhibit a layered internal structure, with layers of ice containing many air bubbles alternating with layers of relatively clear ice .