75077
However , when used on oak , remaining traces of iron may react with tannins in the wood to produce blue or black iron stain , and when used on aluminum , brass , or other non-ferrous metal surfaces may cause after-rust which will dull and discolor the surface .
 plant: oak
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: oak 
Answer:
 plant: oak