16890
Acetylcholinesterase activity did not change in earthworms in the standardised behavioural test ( 0 . 58 +/- 0 . 20 U / mg protein , mean +/- SD ; n = 72 ) , whereas the CbE activity was significantly inhibited ( 62 - 87 % inhibition ) in earthworms exposed to 3 and 15 mg / kg .
 None
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 None