Assertion: vertebral column's curve | /r/HasProperty | natural
Facets:
Source sentences:
text: When viewed from the side, an adult spine has three natural curves that resemble an “S” shape.
text: When viewed from the side, an adult spine has a natural S-shaped curve.
text: The spine has three natural curves that form an S-shape; strong muscles keep our spine in alignment.
text: The spine has four natural curves.