beg the question vs cover up

beg the question

verb
  • To sidestep or fail to address a question. 

  • To raise or prompt a question. 

  • To engage in the logical fallacy of begging the question (petitio principii). 

cover up

verb
  • To conceal or disguise. 

  • To clothe. 

  • To put covers over oneself in bed. 

How often have the words beg the question and cover up occurred in a corpus of books? (source: Google Ngram Viewer )