comb through vs vet

comb through

verb
  • To examine scrupulously. 

vet

verb
  • To thoroughly check or investigate particularly with regard to providing formal approval. 

noun
  • A veteran (a former soldier or other member of armed forces). 

  • A veterinarian or veterinary surgeon. 

How often have the words comb through and vet occurred in a corpus of books? (source: Google Ngram Viewer )