51565
Lamellar bone , which makes its first appearance in humans in the fetus during the third trimester , is stronger and filled with many collagen fibers parallel to other fibers in the same layer ( these parallel columns are called osteons ) .
 animal: fetus
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: media, plant, vehicle, astronomical object, time, disease, animal, location, person, organization, mythical figure, food, biology, geographical phenomenon, instrument, event 
Text: {0} 
 Entities: fetus 
Answer:
 animal: fetus