1218
We prove that while IBM Models 1-2 are conceptually and computationally simple , computations involving the higher -LRB- and more useful -RRB- models are hard .
 IBM Models 1-2, models
Please list all entity pairs containing a certain relationship in the given options.Output format is "word1, word2; word3, word4". 
Option: conjunction, feature of, hyponym of, used for, part of, compare, evaluate for 
Text: {0} 
Answer:
 IBM Models 1-2, models