例句與造句

1. The cervical embrasure usually is filled by the interdental papilla from the gingiva; in the absence of adequate gingival tissue a black angle, or Angularis Nigra is visible.
2. Previously, lack of proper termology to report this condition was an issue, often colloquially termed the " black triangle "; " angularis nigra " was coined at the University of Toronto Faculty of Dentistry.
3. It's difficult to find angularis nigra in a sentence. 用angularis nigra造句挺難的