Sentence:  A brisk , amusing man , apparently constructed on an ingenious system of spring-joints attuned to the same peppery rhythm as his mind , Smith began his academic career teaching speech to Barnard girls - a project considerably <WSD>enlivened</WSD> by his devotion to a recording about `` a young rat named Arthur , who never could make up his mind '' . 
Meaning of the word marked with <WSD> tags:  make lively