Assertion: mammal | /r/HasProperty | placental mammals
Facets:
Source sentences:
text: There are three subclasses of mammals, placental mammals which carry their young in a womb with a placenta, and deliver a relatively full-formed infant, marsupials which do not have a placenta and deliver a relatively un-formed infant that continues its development inside an external pouch, nourishing itself with milk from the mothers mammary glands, and monotremes which lay eggs.(check them out).
text: They are also known as placentals.