1620
We motivate our model design by citing relevant research on second language and cognitive skill acquisition , and briefly discuss preliminary empirical evidence supporting the design .
 second language and cognitive skill acquisition, model design
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:
 second language and cognitive skill acquisition, model design