Assertion: ski | /r/MadeOf | wood
Facets:
Source sentences:
text: At the same time, equipment evolved from skis and poles that were made of wood and other natural materials to comprising such man-made materials as fiberglass, carbon fiber, and polyethylene plastics.
text: Back when skis were made of wood and worn not for competition but to get around in the cold snowy conditions of Scandinavia, skiers simply used animal fat or pine pitch and rosin to waterproof their wooden skis.