6938
Peptide groups in the alpha - helices and the beta - strands of the dimer ( the beta - strands of the monomer ) experience strong and highly asymmetric local ordering centered approximately at the C ( i - 1 ) ( alpha ) - C ( i ) ( alpha ) axes ( N - H bonds ) .
 Chemical: N - H
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: N - H