Assertion: birch's wood | /r/ObjectUse | used as material
Facets:
value: for building ships
type: PURPOSE
Source sentences:
text: The wood of sassafras trees has been used as a material for building ships and furniture in China, Europe, and the United States, and sassafras played an important role in the history of the European colonization of the American continent in the 16th and 17th centuries.